distribute	reads
0-500	825816
500-800	569135
800-1000	253021
1000-1200	204484
1200-1400	171111
1400-1600	146863
1600-1800	128972
1800-2000	114825
2000-2200	102817
2200-2400	92784
2400-2600	84256
2600-2800	75907
2800-3000	67817
>3000	566293
