distribute	reads
0-500	3572
500-800	4415
800-1000	3504
1000-1200	4465
1200-1400	5936
1400-1600	8653
1600-1800	12941
1800-2000	17735
2000-2200	19596
2200-2400	17487
2400-2600	13713
2600-2800	10295
2800-3000	7929
>3000	25043
