distribute	reads
0-500	11133
500-800	5811
800-1000	3275
1000-1200	3001
1200-1400	2733
1400-1600	2727
1600-1800	2298
1800-2000	2236
2000-2200	1980
2200-2400	1859
2400-2600	1703
2600-2800	1626
2800-3000	1548
>3000	29418
