这是今年的难度增长表。

23-Jan-13   2,968,775   N/A
8-Jan-13   3,249,550   9.46%
5-Feb-13   3,275,465   0.80%
18-Feb-13   3,651,012   11.47%
1-Mar-13   4,367,876   19.63%
14-Mar-13   4,847,647   10.98%
24-Mar-13   6,695,826   38.13%
5-Apr-13   7,673,000   14.59%
30-Apr-13   10,076,293   31.32%
14-May-13   11,187,257   11.03%
25-May-13   12,153,412   8.64%
5-Jun-13   15,605,633   28.41%
16-Jun-13   19,339,258   23.92%

平均来说，这六个月来每周增长是超过8%的。