distribute	reads
0-500	617
500-800	1662
800-1000	1336
1000-1200	1958
1200-1400	2489
1400-1600	2756
1600-1800	2914
1800-2000	2875
2000-2200	2807
2200-2400	2776
2400-2600	2550
2600-2800	2554
2800-3000	2354
>3000	27632
