I have two methods that I would like to compare (A and B). I have tested both methods on the same sample (n=28) from a large population. Method A gave the correct result 11 times but method B gave the correct result 17 times. I think that this indicates that method B is 17/11-1 = 55% better than method A. As well as this point estimate for the difference between the methods, I would like to understand the uncertainty caused by my small number of samples. How can I construct a 95% CI for the 55% improvement in performance please?

In 11 cases, both test A and test B worked.

In no cases, test A did work but test B didn't work.

In 6  cases, test A didn't work but test B did work.

In 11 cases, both test A and test B didn't work.