I believe that those figures have both Canon and Nikon dropping their share of the market from 2009 due to the inclusion of mirrorless cameras.
2010: Canon 32.1% of the total, Nikon 26.8 % of the Total
2009: Canon 37.9% of the Total, Nikon 28.1 % of the Total http://www.radiantlite.com/2009/12/digital-slr-sales-in-japan.html
Nikon dropped a little, but Canon took a huge drop. That 32.1% is a 15.3% drop relative to 37.9% in 2009. (37.9-32.1)/37.9 = .153 (15.3%), while Nikons drop is (32.1-26.
/32.1 =.046 (4.6%)
I'm sure that this is not lost on either of them, and new systems are being developed.