distribute	reads
0-500	80
500-800	115
800-1000	294
1000-1200	1000
1200-1400	2811
1400-1600	6875
1600-1800	11932
1800-2000	15618
2000-2200	15188
2200-2400	12852
2400-2600	9966
2600-2800	7600
2800-3000	5583
>3000	8678
