distribute	reads
0-500	79268
500-800	44869
800-1000	25205
1000-1200	22555
1200-1400	19983
1400-1600	18332
1600-1800	16599
1800-2000	14655
2000-2200	13510
2200-2400	12287
2400-2600	11316
2600-2800	10429
2800-3000	9617
>3000	137919
