2^ sz blocks %blcks %keys
28  1 255952 40.66% 15.02%
29  2  58819  9.34%  6.90%
    3  45487  7.23%  8.01%
30  4 245070 38.93% 57.51%
    5   1593  0.25%  0.47%
    6   1767  0.28%  0.62%
    7   1087  0.17%  0.45%
31  8  17565  2.79%  8.24%
    9      8  0.00%  0.00%
   10      6  0.00%  0.00%
   11      9  0.00%  0.01%
   12     10  0.00%  0.01%
   13      7  0.00%  0.01%
   14      2  0.00%  0.00%
   15      3  0.00%  0.00%
32 16   1405  0.22%  1.32%
   17      3  0.00%  0.00%
   18      2  0.00%  0.00%
   19      0  0.00%  0.00%
   20      2  0.00%  0.00%
   21      0  0.00%  0.00%
   22      1  0.00%  0.00%
   23      2  0.00%  0.00%
   24      3  0.00%  0.00%
   25      3  0.00%  0.00%
   26      3  0.00%  0.00%
   27      0  0.00%  0.00%
   28      0  0.00%  0.00%
   29      1  0.00%  0.00%
   30      0  0.00%  0.00%
   31      1  0.00%  0.00%
33 32    747  0.12%  1.40%