distribute	reads
0-500	253791
500-800	8598
800-1000	554
1000-1200	116
1200-1400	34
1400-1600	5
1600-1800	2
1800-2000	0
2000-2200	1
2200-2400	0
2400-2600	0
2600-2800	0
2800-3000	1
>3000	0
