69.5% of filers by count in the bottom groups, generate 10.5% of tax revenue, max refund, 79% of total refund.
4.5% of filers in the top groups, generate 55.2% of tax revenue, zero refund.
Middle two groups are 12.3% and 14.2% of payers, generate 8.8% and 25.5% of revenue, receive 10.6% and 10.3% of total refund.
These categories don't match exactly, but close enough.