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.
A Lowess (locally weighted scatterplot smoothing) curve is used to describe the trend of the data. Data points are slightly jittered (adding random noise to data) in order to prevent overplotting of data points.
