May 2020

The labels for Canada and the UK were reversed in the image of Figure 5a-11 and have been corrected in all viewing and downloading options. The Excel data download was not affected.

Percentages for Japan and India have been corrected in table S5a-17 and figure 5a-4. Text referencing figure 5a-4, located in the section Publication Output, by Field of Science, were also corrected.