distribute	reads
0-500	665
500-800	1829
800-1000	1615
1000-1200	2192
1200-1400	2769
1400-1600	2987
1600-1800	3140
1800-2000	3041
2000-2200	3010
2200-2400	2962
2400-2600	2812
2600-2800	2712
2800-3000	2606
>3000	33760
