See, for example, Webster et al. (2005). This paper has some interesting graphs too, but the time span is short.
We conclude that global data indicate a 30-year trend toward more frequent and intense hurricanes, corroborated by the results of the recent regional assessment.
I should also note that determining causality and determining whether there's a statistically significant upward trend are technically different endeavors. You can have one without the other. This applies to other effects of AGW as well, like sea level rise. Does that make sense?