No significant change in prevalence was found between 1982 and 1990.
There were no significant changes in the prevalence of sexual risk behaviors from 2005 to 2007.
It decreased in prevalence from 1995 to around 10% of all cases.
It is not a new tactic, but has seen an increase in prevalence over the past few decades.
This is seen in the prevalence of child labour among the community.
However, over the same period, several diseases have increased in prevalence and/or severity.
Differences in prevalence due to race and ethnicity are unknown.
A later decline in prevalence may be due to tooth loss.
The police reported a 40% decrease in prevalence, but also that it had moved to more discrete areas and hours.
That is why it is very much a European disease growing in prevalence.