distribute	reads
0-500	2976
500-800	1214
800-1000	1081
1000-1200	1507
1200-1400	2185
1400-1600	3317
1600-1800	4128
1800-2000	4180
2000-2200	3502
2200-2400	2870
2400-2600	2252
2600-2800	1785
2800-3000	1316
>3000	2763
