Please answer a question about the following article about North Carolina:

Severe weather occurs regularly in North Carolina. On the average, a hurricane hits the state once a decade. Destructive hurricanes that have struck the state include Hurricane Fran, Hurricane Floyd, and Hurricane Hazel, the strongest storm to make landfall in the state, as a Category 4 in 1954. Hurricane Isabel stands out as the most damaging of the 21st century. Tropical storms arrive every 3 or 4 years. In addition, many hurricanes and tropical storms graze the state. In some years, several hurricanes or tropical storms can directly strike the state or brush across the coastal areas. Only Florida and Louisiana are hit by hurricanes more often. Although many people believe that hurricanes menace only coastal areas, the rare hurricane which moves inland quickly enough can cause severe damage; for example, in 1989, Hurricane Hugo caused heavy damage in Charlotte and even as far inland as the Blue Ridge Mountains in the northwestern part of the state. On the average, North Carolina has 50 days of thunderstorm activity per year, with some storms becoming severe enough to produce hail, flash floods, and damaging winds.

Hoe often do hurricanes hit North Carolina?
once a decade