Great chart below showing gold as a percent of total global financial assets from 1968 through today. Even with a 5 fold rise in the gold price from the year 2000, its percentage of total assets has remained less than 1%! Why?
The amount of paper assets flooding the system has dwarfed the size of gold's price rise so far.
I believe gold will make up a larger percentage of global assets moving forward but it will not be because of a large increase in gold supply. It will be the paper value of gold re-valuing itself higher to account for the increase in global paper assets.
Then we have the percentage gold or gold mining stocks in a typical pension fund, which is the only picture you need to show anyone who tells you that gold is in a bubble.