The Australian Bureau of Statistics has some interesting data about marriages in Australia during 2006 - marriage is on the up and up!
"In 2006, there were 114,222 registered marriages, an increase of 4,899 (4.5%) from 2005. This is the highest number of registrations since 1999 ... In 2006, marriages performed by civil celebrants again outnumbered marriages performed by ministers of religion. ... By 2006, this proportion had increased to 61.3%" (of all marriages)
There's also data about the age at which couples are marrying, where they were born and whether they cohabited prior to marriage. Interesting stuff.