Good tips, although I'm not sure if the ratio means anything. When I was young I'd happily apply to jobs even if I didn't match on everything in the ad, even though the end chance of getting the position was lower no matter how well I interviewed.

Now that I'm older and have a job I like I usually pop out a really high salary number as early in the process as possible to scare away any companies that would take a lot of work to interview with and then not be able to afford me.

So you could have a very low ratio of offers for reasons other than your interview performance. :)