More than a decade has now passed since the Amish study.

Since the 1959 study, though, the statistic has been reinforced by most other clinical studies, which also showed people with discouraging results.

Since the study by the FHA the number of vehicles has increased by approximately eleven million, one of the largest recorded increases.

It is found that the Baiga population has grown steadily since the first anthropological study of the tribe in the 1930s.

And the difference in heights appears to have increased since the study, said a university researcher, Michael Flanagan.

Of the 26 bridges inspected by Mr. Goldin's staff, 14 were found improved since the 1978 study, while 12, or 46 percent, had structural defects.

He also said the power levels of cell phones had increased since the study.

In the seven years since the last such study, the overall unintended-pregnancy rate has remained unchanged; for women below the poverty level it increased 29 percent.

The estimated construction costs of the scheme have doubled since the 2002 'feasibility' study and have increased by 500% since the first scoping study.

Some mental health experts say parental fears may be misplaced and that overall black racial pride has increased substantially since the 1947 study.