Which sentence demonstrates correct use of the semicolon?

Question 5 options:

There have been many accidents during airshows for example; last year the wind toppled a tent and equipment on top of bystanders.


There have been many accidents during airshows; for example, last year the wind toppled a tent and equipment on top of bystanders.


There have been many accidents during airshows for example, last year; the wind toppled a tent and equipment on top of bystanders.


There have been many accidents; during airshows for example, last year the wind toppled a tent and equipment on top of bystanders.