I want to know the answer to the following question:
What is the ratio that anthropogenic and natural emissions occur at?
All the background I'm provided with is that "After increasing 10-fold from 1850, zinc emissions peaked at 3.4 million tonnes per year in the 1980s and declined to 2.7 million tonnes in the 1990s, although a 2005 study of the Arctic troposphere found that the concentrations there did not reflect the decline.". Is that enough to answer the question?