distribute	reads
0-500	3241
500-800	1585
800-1000	997
1000-1200	1096
1200-1400	1292
1400-1600	2084
1600-1800	4219
1800-2000	8902
2000-2200	14809
2200-2400	22174
2400-2600	29791
2600-2800	35646
2800-3000	43391
>3000	321315
