<human>: Question: What is the ratio that anthropogenic and natural emissions occur at?
Answer: 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 the question answered in a satisfactory fashion?

OPTIONS:
- yes
- no
<bot>: no