I couldn’t tell you what’s considered “normal,” but in my 4 years working on a Marine Corps flight line, I saw 4 or 5 go down. Three in North Carolina and one or two in Japan. Funny thing was, they were all the same plane. The AV8 Harrier. Appropriately nicknamed “The Widow Maker”. Something about vertical takeoffs and one engine that makes a plane dangerous.
Anyhow, those were crashes that I was actually present to see. I heard of many crashes of US aircraft throughout the world because of my job. I don’t think Taiwan’s crashes are abnormal…but just my guess.
To end with some humor, I once saw a plane crash on the GROUND. In this case, there was no pilot. It was during an airshow…at the very end…when a bus carrying tourists plowed into an Airforce B1 Bomber. It took off about 4 feet of the top of the bus. Not sure what the driver was thinking…but he sure cost the US a lot of tax dollars to X-ray the entire plane for damages and replacement parts. Wonder what happened to him…