x     cv
1   34.366310
2   28.211625
3   24.606090
4   23.087880
6   20.931117
8   19.241878
9   19.011100
12  17.658682
16  16.552080
18  16.037840
24  15.138916
32  13.523545
36  13.746140
48  12.393694
64  11.196900
72  12.107256
96   9.910051
144  9.336682
192  8.098715
288  7.720212
384  3.738406
576  5.981003