distribute	reads
0-500	97847
500-800	99228
800-1000	49787
1000-1200	38251
1200-1400	29672
1400-1600	23096
1600-1800	18370
1800-2000	14666
2000-2200	12163
2200-2400	9983
2400-2600	8577
2600-2800	7180
2800-3000	6184
>3000	94425
