distribute	reads
0-500	1775
500-800	1396
800-1000	1128
1000-1200	1570
1200-1400	2576
1400-1600	4387
1600-1800	7367
1800-2000	10893
2000-2200	15502
2200-2400	19892
2400-2600	22367
2600-2800	24845
2800-3000	23822
>3000	150327
