For the first time in nearly 50 years, the average cholesterol level for U.S. adults is in the ideal range, according to a new government report.

Results from a national blood test survey found the average total cholesterol level was 199. Doctors like patients to have total cholesterol readings of 200 or lower.

The growing use of cholesterol-lowering pills in people 60 and older is believed to be a main reason for the improvement, said Susan Schober of the National Center for Health Statistics, the lead author of the report.

"These age group are the ones most likely to be treated with medication," said Schober, a senior epidemiologist.

The survey collects data in two-year intervals. The new results are based on a national sample of about 4,500 people 20 and older from 2005-06. The new 199 level compares with 204 in 1999-2000.

When the survey first began in 1960, the average cholesterol was at 222.

Researchers also found that the percentage of adults with high cholesterol, of 240 or higher, dropped to 16 percent, down from 20 percent in the early 1990s.

They also reported that 65 percent of men and 75 percent of women had been screened for high cholesterol in the previous five years.