To solve this question we have to make deduct these 2 years. 2118 minus 1978 will give the answer.
You are 140 years old.
(1680 months are passed.)
From 1978 to 2118 there are 140 years. If you want to learn your age in 2118 (born in 1978) your age is 140.
Let's see what will be your age if you born +1 or -1 from that date.