Look at *differences* between words rather than at the words themselves?

[radapox]

Also time yourself while doing it, so we can answer multiple questions at once 

 In the meantime I added this edit to my previous reply, so for maximum confusion I'll repeat it here:

On a more serious note: I think a complicating factor is that a lot depends on how you map the mutations to the letters of your source language. If, for instance, frequent letters happen to correspond to more "drastic" mutations (ones with few zeros, in my method), adjacent words would become less similar than if the reverse were the case. So I expect that one source language may yield entirely different TTR results depending on your mapping.