How much importance would you attach to a school's attrition rate?

One of the programs I'm applying to recently posted on their website that last year they were at 20% (previously ~10%/year).

This seems like a red flag to me. I guess its possible to have a "fluke" bad year?

I visited the school and it seemed like a good program. All of the students seemed intelligent and engaged, the school is ranked highly on US news list of CRNA programs.