My apologies, that was my mistake. I accidentally misplaced a hurricane from 1989 to 1969 when I created charts from Klotzbach's table. My eyes obviously need testing. I've asked the editor to replace the image with a corrected version. 

It doesn't make much difference to the conclusion, however. There is still no clear trend in strong hurricanes, and the interwar period actually had more strong hurricanes than any other time period. The fact that there were two double years recently also makes little difference. In fact, they bracket 12 years with no landfalling hurricanes in the US at all.

The other chart, of global accumulated cyclone energy, confirms that there is no trend in cyclones associated with climate change.