Cigarette sales in the United States have reached the lowest point since 1951, according to data compiled by the U.S. Department of Agriculture.

The number of cigarettes sold in the U.S. rose steadily from 375 billion in 1950 to a peak of 640 billion in 1981, then declined to 485 billion in 1993. From 1993 to 1997, the number of cigarettes sold plateaued, then began to decrease again in 1998. In 2005, 378 billion cigarettes were sold.

Factors influencing this decline include advertising restrictions and increased cigarette prices stemming from the 1998 tobacco Master Settlement Agreement, legislation restricting where people can smoke, and greater knowledge of the health risks associated with smoking.

For details, including data charts, source information and caveats, download the PDF file at www.cesar.umd.edu/cesar/cesarfax/vol15/15-29.pdf.

Reprinted from CESAR Fax, a weekly, one-page overview of timely substance abuse trends or issues, from The Center on Substance Abuse Research (CESAR) at the University of Maryland.