Interpolate-Missing-Data-Points

// Create a list of dates to use as data points
// Count the amount of days since the creation date
int dayCount = DateTime.Now.Subtract(createdDate).Days;

// Create an index of data points and calculate linear interpolation for a given point
int[] membershipPoints = new int[dayCount];

for (int i = 0; i < membershipPoints.Length; i++)
{
    // Calculate membership count using linear interpolation
    membershipPoints[i] =  (int)(((float)mg.members / ((float)membershipPoints.Length)) * (float)i);
}