Auto-updating cell evaluated by date

I've been struggling to write a formula to have a cell display the percentage for this month and like it, another cell that displays last month's percentage, auto-updating per month. I'm come up with a formula that works, but it's hideous coding.

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Are there any simpler ways to do this? H2 and on is the list of values starting November '07 and on. The only coding I ever played with is "spaghetti code" Basic, and I guess old habits die hard. The code I used for last month is:

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Obviously it will have to be rewritten every year.