I have an array of numbers sorted by ascending date. These numbers are filled when there are blanks with the values from above. eg:


11/04/2016 1 2 1
12/04/2016 2 4 2
13/04/2016 3 6 3
14/04/2016 4 2 3
15/04/2016 4 3 3
16/04/2016 4 9 3

I need to find the corresponding date of the last unique value (from the bottom up). So 14/04/2016 for Column B for instance.
I have tried various combinations of index(match,match) and lookup(1,1/Array) methods but no luck. Any thoughts? I unfortunately cannot change the source array at all, only reference it.
Thanks