the GSR is a subjective number. The 75:1 is for paper gold and silver. So depending which country you are in and what your premiums and vat levels are all come into the ratio

I did a post last week about the true uk gold and silver ratio and it ain't no where near 75:1 .. if you sold gold to buy silver its about 57 to 1

https://steemit.com/bullion/@dune69/what-is-the-actual-gold-to-silver-ratio-gsr-in-the-uk-75-1