If you take a look at the studies you'll find old data has issues because of changes in how hurricanes were measured. Hurricanes are now monitored by satellites. Many of them are short lived and never seen by a ship or other system that would record it. Data collection prior to satellites would not have observed these.
A good resource can be found at https://www.gfdl.noaa.gov/global-warming-and-hurricanes/. They talk about normalizing the data and look at the impact of global warming on hurricanes. Numerous studies are quoted.