distribute	reads
0-500	3276
500-800	1868
800-1000	1310
1000-1200	1487
1200-1400	1895
1400-1600	2753
1600-1800	4206
1800-2000	6393
2000-2200	9282
2200-2400	12887
2400-2600	16982
2600-2800	20174
2800-3000	22705
>3000	229326
