How long do humans live in reference to the time scale of the universe?

Almost nothing.

The Universe is about 14 billion years old, and what we could call humans exist only for about 1 million years.

If you scale the age of the universe into one year, humans would appear:

##1/14000xx365xx24xx60=37## minutes before midnight of December 31st

For the particular and proud Homo Sapiens (200 thousand years) it would be:

##0.2/14000xx365xx24xx60=7.5## minutes before midnight of December 31st