Comparing inlining method and no inlining method

InlineMethodExample.cs

using System.Diagnostics;
using System.Runtime.CompilerServices;

class Program
{
    const int MAX = 10000000;

    static void Main()
    {
        // ... Compile the methods.
        Add_NoInlining(4, 5);
        Add_Inlining(8, 9);
        int sum = 0;

        var s1 = Stopwatch.StartNew();
        for (int i = 0; i < MAX; i++)
        {
            sum += Add_NoInlining(i, i-1);
        }

        s1.Stop();
        var s2 = Stopwatch.StartNew();
        for (int i = 0; i < MAX; i++)
        {
            sum += Add_Inlining(i, i-1);
        }
        s2.Stop();

        Console.WriteLine(((double)(s1.Elapsed.TotalMilliseconds * 1000000) / MAX).ToString("0.00 ns"));
        Console.WriteLine(((double)(s2.Elapsed.TotalMilliseconds * 1000000) / MAX).ToString("0.00 ns"));
    }

    [MethodImpl(MethodImplOptions.NoInlining)]
    static int Add_NoInlining(int x, int y)
    {
        return x + y;
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    static int Add_Inlining(int x, int y)
    {
        return x + y;
    }
}