The .gov means it's official. Federal government websites often end in .gov or .mil. Before sharing sensitive information,
make sure you're on a federal government site.
The site is secure. The
https:// ensures that you are connecting to the official website and that any
information you provide is encrypted and transmitted securely.
During 1972-81, output per hour increased at an annual rate of 1.4 percent, slowing to less than 1 percent after 1976; growth in productivity has been linked to improved technology.