distribute	reads
0-500	1931
500-800	824
800-1000	523
1000-1200	627
1200-1400	884
1400-1600	1596
1600-1800	2686
1800-2000	4297
2000-2200	6529
2200-2400	8814
2400-2600	11440
2600-2800	13705
2800-3000	15189
>3000	154652
