distribute	reads
0-500	49754
500-800	40343
800-1000	20895
1000-1200	17753
1200-1400	15083
1400-1600	12986
1600-1800	11158
1800-2000	9791
2000-2200	8636
2200-2400	7735
2400-2600	6662
2600-2800	5914
2800-3000	5456
>3000	56193
