I have a (java) solution, which gives 100%, but has a serious bug in it. It can not detect the correct periods if the first two (n?) digits (other than 0) are equal.
The provided test-cases does not have such values. So the program is correct with regard to the tests, but wrong regarding the puzzle goal.
My Suggestion is to add 44 => 0.02(27) and 84 => 0.01(190476) to the test-cases.