distribute	reads
0-500	1013
500-800	3669
800-1000	3320
1000-1200	4358
1200-1400	5170
1400-1600	5396
1600-1800	5486
1800-2000	5350
2000-2200	5285
2200-2400	5053
2400-2600	4676
2600-2800	4435
2800-3000	4268
>3000	68051
