First published by Money Metals here: https://www.moneymetals.com/news/2017/05/15/global-silver-supply-demand-001072

Estimates for 2016 are in and the data shows the first decline in silver mine output in 14 years. The Silver Institute’s World Silver Survey 2017 shows reduced production of the base metals lead and zinc are largely to blame, though silver production as a byproduct of gold mining also fell.