Since each round is timed, they're predictable every year. The first round for 2012 lasted just over 3 hours; the 2013 first round draft lasted about 3 hours, 30 minutes.
The first crusade lasted for 3 years.
20 years
9 999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999million years
8 years
20 years
The Constitution lasted 8 years.
20 years
20 years
20 years
20 years
Anywhere from 0-5 years
The lifespan of a guinea pig is 5 years.