There is no way of knowing. The farther back you go, the less reliable records become. Accounts from before 1950 are pretty incomplete, and reliable accounts from before 1880 or so are few and far between. There are no reliable accounts of any tornado-related deaths in the United States in 1800, though it is likely that deaths occurred somewhere.
Tornadoes in the U.S. killed 70 people in 2012.
Tornadoes killed 81 people in the U.S. in 2007.
Tornadoes killed 30 people in the U.S. in 1995. It is unknown how many, if any, were killed by tornadoes in the rest of the world.
Worldwide in 2011 574 people were killed by tornadoes including 553 in the U.S.
85 people worldwide were killed by tornadoes in 2006, 67 of them in the U.S.
As of July 25, tornadoes in the US have killed 10 people in 2015.
From 2000 to today in Italy 9 people died from tornadoes. From the 1800 about 650 people died due to tornadoes
In 1990 tornadoes killed 53 people in the U.S. Figures for other countries are not available.
In an average year 60 people are killed by tornadoes and 1500 are injured in some way.
Tornadoes killed 32 people in Tennessee in 2011.
Tornadoes kill 60-80 people in an average year.
Tornadoes in 1953 killed at least 526 people. Tornadoes in the United states killed 519 people, and one in Canada killed 7. Data for other countries is not readily available.