If you look closely, after 1973 (Which is when The Rolling Stones song, “Angie” came out) the name had a spike in popularity. Although the name was already getting popular then, the name reached its peak in 1975 and should probably be credited to The Rolling Stones. [noted -ed]
In 2018, 35 is the most common age for an American (U.S.) Angie* who is registered female with the Social Security Administration. It is the 788th most common female first name for living U.S. citizens. *as a first name, not a nickname.
Sources: https://en.m.wikipedia.org/wiki/Angie_(given_name)
https://en.m.wikipedia.org/wiki/Unisex_name