As a statistician, I note that y axis represents the counts and x-axis represents q(nm^-1). I do not know what is q(nm^-1). Any way when q is at 4, the maximum counts (4000001) are seen. Thereafter the counts falls drastically and reach back to 500001 (12% of the peak counts) by the time q=5 and thereafter the fall in the counts is negligible. So q=4 gives the maximum counts (may be some activity).