distribute	reads
0-500	285
500-800	1183
800-1000	1036
1000-1200	1571
1200-1400	1823
1400-1600	1956
1600-1800	1880
1800-2000	1983
2000-2200	1875
2200-2400	1889
2400-2600	1811
2600-2800	1725
2800-3000	1800
>3000	41449
