distribute	reads
0-500	4507
500-800	2785
800-1000	1854
1000-1200	2032
1200-1400	2467
1400-1600	2939
1600-1800	3857
1800-2000	5560
2000-2200	7770
2200-2400	10903
2400-2600	14697
2600-2800	18783
2800-3000	22987
>3000	220815
