distribute	reads
0-500	1444
500-800	770
800-1000	526
1000-1200	682
1200-1400	859
1400-1600	1314
1600-1800	2104
1800-2000	3096
2000-2200	4250
2200-2400	5132
2400-2600	5256
2600-2800	4721
2800-3000	3505
>3000	9068
