How often do you change & wash your bed sheets?

I came across the results of a recent survey which says many over 40% of single guys in Britain only change their sheets about every 4 months. Sometime longer. WTF? I don't know if this is the norm for most or not. So what is it? How often do you change & wash your bedsheets.
Updates
+1 y
I found a link to the article. I hope it works.
ladbible. com/news/latest-almost-half-of-uk-men-only-change-their-sheets-every-4-months-20220429
How often do you change & wash your bed sheets?
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