distribute	reads
0-500	6247
500-800	21158
800-1000	17439
1000-1200	16595
1200-1400	14947
1400-1600	13338
1600-1800	11342
1800-2000	10069
2000-2200	8695
2200-2400	7529
2400-2600	6532
2600-2800	5474
2800-3000	4641
>3000	21623
