According to a 1983 county study, from 1940 to 1979, the use of salt doubled every five or six years.

Their use has more than doubled in the last 20 years, to 762.1 billion pounds in 1989.

Japan's use of steel framing nearly doubled during the decade.

When doctor and nurse made joint treatment decisions, however, use of the latter almost doubled.

Since 1990, use of the pill has more than doubled among women from 35 to 39 years old.

The use of antidepressants in the United States doubled over one decade, from 1996 to 2005.

In five years, the use nearly doubled, to 150,000 from 80,000 visits a year.

The use of sleeping medicines among adults doubled from 2000 to 2004, Medco found.

They turned to synthetic fertilizer rich in nitrogen, the use of which doubled over a 10-year period.

And we know that the use of fossil fuels will double by the year 2020.