distribute	reads
0-500	16382
500-800	7960
800-1000	4341
1000-1200	4045
1200-1400	3674
1400-1600	3141
1600-1800	2843
1800-2000	2617
2000-2200	2399
2200-2400	2311
2400-2600	2252
2600-2800	2035
2800-3000	1992
>3000	35666
