distribute	reads
0-500	198866
500-800	34631
800-1000	4358
1000-1200	1217
1200-1400	388
1400-1600	141
1600-1800	39
1800-2000	13
2000-2200	7
2200-2400	3
2400-2600	1
2600-2800	0
2800-3000	0
>3000	0
