In the 1970's, there was an average of about 10 Category four and five hurricanes per year globally. Since 1990, the number of Category four and five hurricanes has almost doubled, averaging 18 per year globally.  -   Peter Webster     Quotes
In the 1970's, there was an average of about 10 Category four and five hurricanes per year globally. Since 1990, the number of Category four and five hurricanes has almost doubled, averaging 18 per year globally. Peter Webster