distribute	reads
0-500	5997
500-800	5833
800-1000	3577
1000-1200	4110
1200-1400	4728
1400-1600	5780
1600-1800	7621
1800-2000	9800
2000-2200	12163
2200-2400	15494
2400-2600	19322
2600-2800	23369
2800-3000	28374
>3000	788803
