distribute	reads
0-500	414315
500-800	214804
800-1000	93610
1000-1200	74257
1200-1400	62508
1400-1600	53546
1600-1800	47236
1800-2000	42981
2000-2200	39418
2200-2400	37266
2400-2600	35051
2600-2800	33381
2800-3000	32407
>3000	1588573
