Statistical significance is measured at the 5% significance level (
p
value < .05).
Statistically significant differences between survey years (
p
< .05) are indicated by the symbols
and
(significant increase or decrease respectively).
The symbol
≈
indicates there is no statistically significant difference between survey years.
A statistically significant difference is likely to represent a real change over time, rather than random variation due to the sampling process.
This table gives the percentage of the population affected (that is, the unadjusted prevalence in the specified population). Click on an indicator to find out more about it.
