distribute	reads
0-500	224
500-800	81
800-1000	84
1000-1200	150
1200-1400	288
1400-1600	471
1600-1800	679
1800-2000	994
2000-2200	1270
2200-2400	1553
2400-2600	1674
2600-2800	1848
2800-3000	1888
>3000	10723
