distribute	reads
0-500	2111
500-800	5481
800-1000	4624
1000-1200	6534
1200-1400	9361
1400-1600	11526
1600-1800	12249
1800-2000	12395
2000-2200	12427
2200-2400	12033
2400-2600	11511
2600-2800	11079
2800-3000	10301
>3000	85550
