To solve this question we have to make deduct these 2 years. 2105 minus 1990 will give the answer.
You are 115 years old.
(1380 months are passed.)
From 1990 to 2105 there are 115 years. If you want to learn your age in 2105 (born in 1990) your age is 115.
Let's see what will be your age if you born +1 or -1 from that date.