single engine attrition rate vs twin engine

has single engine technologies improved over the years?

http://www.f-16.net/fleet-reports_article6.html

hundreds of F-16s lost due to attrition
about 10 F-15’s lost (in 2003).

we are not sure how many of these F-15s and F-16s are lost due to engine failure.. but it could be assumed that if the F-16 was a twin, one engine that could survive, would bring the airplane back and not cause total aircraft lost?

for maritime countries is this a big factor towards twins?

what is the attrition rate of F-18 vs Gripen F404.