distribute	reads
0-500	2041
500-800	1272
800-1000	1081
1000-1200	1490
1200-1400	2487
1400-1600	4026
1600-1800	5743
1800-2000	6571
2000-2200	5500
2200-2400	3985
2400-2600	2878
2600-2800	2341
2800-3000	1689
>3000	4498
