I don't understand how to get the share prices in returns in order to use in the geometric formula. Please provide explanation.

I don't understand how to get the share prices in returns in order to use in the geometric formula.

Please provide explanation.

What is the geometric average return of a stock with the following share price history?

Year - Share price

1 - $35

2 - $30

3 - $39

4 - $42

5 - $45