distribute	reads
0-500	67162
500-800	21392
800-1000	9529
1000-1200	7799
1200-1400	6050
1400-1600	4899
1600-1800	4113
1800-2000	3367
2000-2200	2878
2200-2400	2508
2400-2600	2090
2600-2800	1775
2800-3000	1574
>3000	13392
