"That would have to be an estimate. I found some accurate statistics for recent years, and you can extrapolate from them. From May 3,1951 to Sep.28, 2011 there were 968 reported tornadoes in Michigan. (No one knows how many more were not reported.) So if this is something you want to rely on, that there were about 960 tornadoes in 60 years, that gives you an estimate of around 16 significant tornadoes per year in Michigan. So multiply 16 by the number of years you are interested in."
"Despite the fact that tornadoes happens to quite a few aspects of the entire world, these dangerous allows involving character are located most regularly in the usa east with the Rocky Piles through the spring and summer months. In a normal calendar year, 1,000 tornadoes are usually documented countrywide, causing seventy-five deaths well as over a single,400 injuries. Tornadoes are likely to occur concerning several and ix r.michael., yet have been proven to arise whatsoever time through the day as well as night. "