I just looked it up and there were 779 SM entries at ST and non ST Majors in 2018. That means that a total of $15,580 was collected. This is not a big number when you start totaling travel for compliance. Just the compliance at ST would eat this figure up quickly.
If I recall correctly, the original SM compliance fee was for all races and was $10. So, that figure would have increased by 3 to 4 times and account for the funds to purchase whistlers, etc. For example, in 2010, there were 3543 regional SM entries. That would have generated $35,430 at $10 per car plus the 1253 National entries that year for another $12,530 or a total of right at $48,000.
I would think the figure will a bit higher this year but no one is going to be able to take early retirement on the compliance fund!