In the following figures, smoothed is a seven day running average.
I tried fitting a cubic function to the cumulative points.
a = 6.87691e+06 +/- 1.452e+05 (2.112%) b = 8.91947e+07 +/- 9.473e+05 (1.062%) c = -2.96506e+07 +/- 1.755e+06 (5.919%) d = 1.04259e+07 +/- 8.753e+05 (8.395%)
Note - The next three graphs use a log scale.