distribute	reads
0-500	158632
500-800	46585
800-1000	14445
1000-1200	8692
1200-1400	5761
1400-1600	3894
1600-1800	2859
1800-2000	2226
2000-2200	1813
2200-2400	1387
2400-2600	1098
2600-2800	969
2800-3000	829
>3000	8267
