The apparent 50% decrease in production by the United States led to a calculated percentage of world production decrease from 56% to 36%; however, a 2013 news article indicated the United States produced at least 80% of the world's supply.
The apparent 50% decrease in production by the United States led to a calculated percentage of world production decrease from 56% to 36%. The United States produced at least 80% of the world's supply. This was what a 2013 news article indicated.