distribute	reads
0-500	15982
500-800	34258
800-1000	19508
1000-1200	13794
1200-1400	8702
1400-1600	5202
1600-1800	2964
1800-2000	1591
2000-2200	775
2200-2400	428
2400-2600	185
2600-2800	100
2800-3000	45
>3000	47
