distribute	reads
0-500	6795
500-800	4207
800-1000	2535
1000-1200	2584
1200-1400	3019
1400-1600	3741
1600-1800	4915
1800-2000	7037
2000-2200	9727
2200-2400	13462
2400-2600	17774
2600-2800	23094
2800-3000	27586
>3000	560549
