Since my bank is not proud enough to display their interest rate on their home page anymore I am struggling to figure this out.
I have an escrow account that looked like
639.14
960.77
1282.4
1604.03
1925.66
2247.29
639.14
960.77
1282.4
1604.03
1925.66
2247.29
I received a measly 2.67 interest for the year of 2013. Enough to not generate a 1099-INT. What is my interest rate? Last year I received 22.18, is it correct to assume that the interest rate drop by about 88% (1-2.67/22.18) or is it different than that since the interest is compounded?
Are you sure you're getting paid interest at all? The difference between any two consecutive numbers in the sequence you give is 321.63. This would seem to indicate that you're putting in 321.63 per month and getting no interest - if you were getting interest (even some very small amount) you'd expect the difference between the month $n$ and month $n + 1$ balances to be larger when the month $n$ balance is larger.
Edited to add: after the OP's comment, the question is a bit clearer. In that case, I'd observe that the average balance in the account (the average of the twelve numbers above) is 1443.22. If you received 2.67 in interest, then the interest rate (assuming it didn't change over the course of the year) is 2.67/1443.22 or about 0.185 percent. I'm not surprised your bank doesn't bother to make this rate public, because it's so low.