distribute	reads
0-500	548
500-800	2767
800-1000	2558
1000-1200	2840
1200-1400	3054
1400-1600	2948
1600-1800	2793
1800-2000	2489
2000-2200	2158
2200-2400	2035
2400-2600	1768
2600-2800	1521
2800-3000	1310
>3000	9767
