How long should a man take to propose?

Currently in a relationship, and honestly I want to marry him, he feels the same. We were joking around and I said don’t take more than a year to propose, and it got me thinking, why wait so long if you know what you want? (I’m a strong believer in the institution of marriage due to my beliefs, so that’s one of my reasons). But it’s not even that I’m trying to rush it, I just don’t think I’d like knowing who I want to be with and not being able to make it official. Thoughts?