To solve this question we have to make deduct these 2 years. 2100 minus 1990 will give the answer.
You are 110 years old.
(1320 months are passed.)
From 1990 to 2100 there are 110 years. If you want to learn your age in 2100 (born in 1990) your age is 110.
Let's see what will be your age if you born +1 or -1 from that date.