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.
Shaded areas indicate the 99% confidence interval. Green curves correspond to non-scrambled blocks, while red curves correspond to data from the scrambled blocks. Asterisks indicate peak values within the significant bins.
