UnitedHealth Group Incorporated operates as a diversified health care company in the United States. UnitedHealthcare offers consumer-oriented health benefit plans and services for national employers, public sector employers, mid-sized employers, small businesses, and individuals. The beta is .63.

UnitedHealths stock prices for the last 6 years are:

Dec 2014 93.05

Dec 2015 110.05

Dec 2016 152.31

Dec 2017 212.99

Dec 2018 243.92

Dec 2019 292.71

1. Calculate the stock returns for the last 5 years: 2015-2019.