Answer:
206.63 %
Step-by-step explanation:
Hello, I can help you with this.
you can easily solve this by using a rule of three
Step one
define the data to use
year:2005
price:513
this is our initial value, the 100 percent (100%)
513⇔100%
then, in 2015 the price was 1060
year:2015
price:1060
%=x( the unknown number)
Step two
do the relation

so, the percentage that the price per ounce of gold increase was 206.63%
I really hope it helps, Have a great day.