We have data back to 1970, but before satellites (~1980), it is probably undercounted. Moreover, 1970s and 1980s were relative hurricane lulls, so starting there can give a spurious upward trend
Still, 2020 was a very un-active year
Global number of hurricanes varies a lot over 50 years, but no significant trends
(cat3+ increasing insignificantly, all decreasing insignificantly)
2020 below average for both all and strong hurricanes
(undercounting likely before 1980, and ignore lull in 1970s+80s)
Undercounting hurricanes in open waters before satellites a significant problem — see here the difference in the two top N Atlantic ACE years, 1933 and 2005
Contrary to breathless climate reporting, number of major landfalling US hurricanes — the most reliable hurricane indicator — has not increased since 1900
(Notice unprecedented major hurricane drought from 2006-16)
Contrary to breathless media reporting, land-falling US hurricanes — the most reliable hurricane indicator — does not show an increasing number of hurricanes since 1900