distribute	reads
0-500	99430
500-800	18748
800-1000	3311
1000-1200	1203
1200-1400	471
1400-1600	190
1600-1800	82
1800-2000	24
2000-2200	9
2200-2400	6
2400-2600	3
2600-2800	0
2800-3000	0
>3000	0
