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.
Solid horizontal line is the line of identity. Black curved line is a smooth curve through the points and was created using 95% of the data. Dashed grey lines are quantile regressions of the 5th and 90th percentiles of the differences which measures precision. The grey dotted vertical line indicates 30% errors [45].
