distribute	reads
0-500	15402
500-800	11595
800-1000	8480
1000-1200	9543
1200-1400	11184
1400-1600	14380
1600-1800	19033
1800-2000	26123
2000-2200	34948
2200-2400	44914
2400-2600	54760
2600-2800	64636
2800-3000	70672
>3000	669226
