C# Calculate Items or Bytes Per Second

CalculateItemsPerSecond.cs

public class CalculateItemsPerSecond
    {
        private readonly int       _limit;
        private readonly Stopwatch _timer;
        private          bool      _running;
        /// <summary>
        ///     Uses the average of a number of readings, so that the results are not as sporadic.
        /// </summary>
        private LimitedList<double> _rvlst;
        private double _tSeconds;
        public  string ElapsedTime;
        public  string RemainingTime;
        public  string TotalTime;
        public CalculateItemsPerSecond(int limit = 30)
        {
            _timer        = new Stopwatch();
            _limit        = limit;
            _running      = false;
            _rvlst        = new LimitedList<double>(_limit);
            _tSeconds     = 0;
            ElapsedTime   = "Calculating...";
            RemainingTime = "Calculating...";
            TotalTime     = "Calculating...";
        }
        private void CalculateERT(double Percent)
        {
            var Ratio     = 100.0 / Percent;
            var ctSeconds = _tSeconds * Ratio;
            var etsr      = new TimeSpan(TimeSpan.FromSeconds(_tSeconds).Ticks);
            ElapsedTime = $"{etsr.Hours:00}:{etsr.Minutes:00}:{etsr.Seconds:00}";
            var rtsr = new TimeSpan(TimeSpan.FromSeconds(ctSeconds).Subtract(TimeSpan.FromSeconds(_tSeconds)).Ticks);
            RemainingTime = $"{rtsr.Hours:00}:{rtsr.Minutes:00}:{rtsr.Seconds:00}";
            var tts = new TimeSpan(TimeSpan.FromSeconds(ctSeconds).Ticks);
            TotalTime = $"{tts.Hours:00}:{tts.Minutes:00}:{tts.Seconds:00}";
        }
        /// <summary>
        ///     Starts the timer, and sets running, and reset the limited list.
        /// </summary>
        public void Start()
        {
            _rvlst = new LimitedList<double>(_limit);
            _timer.Restart();
            _running = true;
        }
        /// <summary>
        ///     Stops the timer and sets as not running.
        /// </summary>
        public void Stop()
        {
            _timer.Stop();
            _running = false;
        }
        /// <summary>
        ///     Returns the Items Per Second at the time called relative to the start() command.
        ///     If totalItems is not zero, then times (Elapsed,Remaining,Total) will also be calculated.
        /// </summary>
        /// <param name="itemsProcessed">The number of items processed so far.</param>
        /// <param name="totalItems">The total number of items to be processed.</param>
        /// <returns>The Items Per Second</returns>
        public double ItemsPerSecond(int itemsProcessed, int totalItems)
        {
            return ItemsPerSecond(itemsProcessed, (double) totalItems);
        }
        /// <summary>
        ///     Returns the Items Per Second at the time called relative to the start() command.
        ///     If totalItems is not zero, then times (Elapsed,Remaining,Total) will also be calculated.
        /// </summary>
        /// <param name="itemsProcessed">The number of items processed so far.</param>
        /// <param name="totalItems">The total number of items to be processed.</param>
        /// <returns>The Items Per Second</returns>
        public double ItemsPerSecond(uint itemsProcessed, uint totalItems)
        {
            return ItemsPerSecond(itemsProcessed, (double) totalItems);
        }
        /// <summary>
        ///     Returns the Items Per Second at the time called relative to the start() command.
        ///     If totalItems is not zero, then times (Elapsed,Remaining,Total) will also be calculated.
        /// </summary>
        /// <param name="itemsProcessed">The number of items processed so far.</param>
        /// <param name="totalItems">The total number of items to be processed.</param>
        /// <returns>The Items Per Second</returns>
        public double ItemsPerSecond(long itemsProcessed, long totalItems)
        {
            return ItemsPerSecond(itemsProcessed, (double) totalItems);
        }
        /// <summary>
        ///     Returns the Items Per Second at the time called relative to the start() command.
        ///     If totalItems is not zero, then times (Elapsed,Remaining,Total) will also be calculated.
        /// </summary>
        /// <param name="itemsProcessed">The number of items processed so far.</param>
        /// <param name="totalItems">The total number of items to be processed.</param>
        /// <returns>The Items Per Second</returns>
        public double ItemsPerSecond(ulong itemsProcessed, ulong totalItems)
        {
            return ItemsPerSecond(itemsProcessed, (double) totalItems);
        }
        /// <summary>
        ///     Returns the Items Per Second at the time called relative to the start() command.
        ///     If totalItems is not zero, then times (Elapsed,Remaining,Total) will also be calculated.
        /// </summary>
        /// <param name="itemsProcessed">The number of items processed so far.</param>
        /// <param name="totalItems">The total number of items to be processed.</param>
        /// <returns>The Items Per Second</returns>
        public double ItemsPerSecond(float itemsProcessed, float totalItems)
        {
            return ItemsPerSecond(itemsProcessed, (double) totalItems);
        }
        /// <summary>
        ///     Returns the Items Per Second at the time called relative to the start() command.
        ///     If totalItems is not zero, then times (Elapsed,Remaining,Total) will also be calculated.
        /// </summary>
        /// <param name="itemsProcessed">The number of items processed so far.</param>
        /// <param name="totalItems">The total number of items to be processed.</param>
        /// <returns>The Items Per Second</returns>
        public double ItemsPerSecond(double itemsProcessed, double totalItems)
        {
            if ((int) itemsProcessed == 0)
                return 0;
            if (totalItems > 0)
            {
                var p = itemsProcessed * 100.0f / totalItems;
                if (p > 100.0)
                    p = 100;
                CalculateERT(p);
            }
            if (!_running)
                Start();
            _rvlst.Add(itemsProcessed / _timer.Elapsed.TotalSeconds);
            _tSeconds = _timer.Elapsed.TotalSeconds;
            var rv = _rvlst.AverageEx();
            if (rv < 1)
                return 0;
            return rv;
        }
    }