Proposing to my Girlfriend!?

Hi, My name is jorge im 19 years old and im wondering when should i propose to my lovely girlfriend. we been dating for a year but i knew from a long time ago since sophomore year in high school we met and became friend and after graduating we started calling each other and one day i asked her if she wanted to go out with me! when i heard her say yes i became the most happiest man alive!! cuz i really luv her with all my heart! i know is to early to ask this proposing question but im just wondering when should be ther right time 5, 6, or 7 years from now!!