Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Notes: Authors’ analysis of administrative or survey data for each region. The Appendix provides a full description of country- or province-specific data sources (see S1 File). Abbreviated countries are Canada, England, Germany, Japan, the Netherlands, Spain and United States. We do not have information for the Netherlands.
