For or Since

David has worked for the power company ___________ 1990.

His brother has worked for the power company ___________ five years.

I have known Peter Gow ___________ September.

I've known his sister ___________ three months.

Jonas has walked with a limp___________ many years.

He's had a bad leg ___________ he was in the war.

Rachel hasn't been in class ___________ last Tuesday.

She hasn't been in class ___________ three days.

I've had a toothache ___________ yesterday morning.

I've had this toothache ___________ thirty-six hours.