distribute	reads
0-500	1581
500-800	2764
800-1000	1813
1000-1200	1754
1200-1400	1968
1400-1600	2240
1600-1800	2739
1800-2000	3364
2000-2200	4002
2200-2400	4287
2400-2600	4493
2600-2800	4407
2800-3000	4446
>3000	25220
