distribute	reads
0-500	6270
500-800	5351
800-1000	5877
1000-1200	9382
1200-1400	13944
1400-1600	18622
1600-1800	22996
1800-2000	25065
2000-2200	24146
2200-2400	21213
2400-2600	17122
2600-2800	13323
2800-3000	9865
>3000	23168
