1996
School enrollments/beginning of the school year was always late August/early September, so a normal school year (at least here in the U.S.) would run from late August/early September to late May/early June of the next year. Being born in 1977, I guess it depends on when in 1977 you were born. Being born in late August, I graduated high school around the end of May/beginning of June 1995.
You would graduate in the year 2008
If you were born in 1999 you would graduate from high school in the year of 2017.
Most likely 1978, but depending on when your school's cutoff dates are and when in the year you were born it could potentially be a year on either side of that, or more if you either skipped a grade or two or had to repeat a grade or two.
Oh, what a lovely question! If you were born in 1959, and we add 18 years to that, you would graduate in 1977. Just imagine all the happy little memories you would have made during those school years! Remember, there are no mistakes, just happy accidents.
2020
2011
She was born in 1977
If 21 when graduated it will be on the year 1991
If you were born in early to mid '10, you would graduate in '28. However, if you were born in mid to late '10, you would graduate in '29.
if you are in fifth grade then you would graduate in 2018