Given the following share prices at the end of the following years for XYZ Company
	Date	Year-end price
0	31-12-y1	$30
1	31-12-y2	$33
2	31-12-y3	$35
3	31-12-y4	$32
4	31-12-y5	$40
5	31-12-y6	$35
Find arithmetic mean annual yield for the investment in XYZ.