distribute	reads
0-500	42822
500-800	26742
800-1000	15607
1000-1200	14020
1200-1400	12986
1400-1600	12229
1600-1800	10985
1800-2000	10157
2000-2200	9413
2200-2400	8920
2400-2600	8177
2600-2800	7459
2800-3000	6918
>3000	100242
