Satchel owns a home-style Mexican restaurant in Dallas, TX. He is complaining about the price of avocado this year compared to what they used to be 10 years ago. If an avocado that cost $0.80 back in 2012 costs $1.20 in 2021, what is the average "annual growth rate" in the avocado price between 2012 and 2021 (over 10 years)