The number of people tying the knot is at a 20-year high, while fewer of those signing up to conjugal bliss are shedding tears over a failed marriage.

Last year, there were 118,756 marriages registered in Australia, almost 2500 more than the previous year and the highest number in the past two decades. In 1989, there were 117,176 marriages.

The figures are contained in a snapshot of the past 20 years from the Australian Bureau of Statistics that also shows a declining divorce trend.

There were 47,209 divorces granted last year, and the numbers have been steadily falling since they reached more than 52,700 in 2004.

There is also a corresponding decline in the crude divorce rate - that is, the number of people who last year got a divorce out of every 1000 people. That rate has fallen from 2.6 per 1000 people in 2004 to 2.2 per 1000 last year.

When marriages do end, the median length is about 12 years, and almost half of divorces affect children. The crude rate of marriage, however, has remained steady at 5.5 per 1000 people for the past three years, and is still lower than the seven per 1000 back in 1989.

Peter McDonald, head of demographics at Australian National University, said one reason for the divorce decline could be the trend in living together before marriage. Last year, 78 per cent of marriages were preceded by a couple cohabiting.

''Maybe the divorce is taking place before the marriage,'' he said. ''They've lived together and tried out the relationship but break up without marrying.''

The strong economy up until late last year could also have had an impact.

''Marriage breakdown is very much associated with economic circumstances, and if economic circumstances are better, then couples have one less thing to argue about,'' he said.

Australian Institute of Family Studies director Alan Hayes said that as people were a little older when they married than used to be the case, they were probably making more mature decisions. ''They don't go into it wide-eyed and unrealistic; they go into it in the background of what a long-term committed relationship is like and what the challenges are,'' he said.

''It's around the maturity to understand the nature of give and take, and the extent to which you do have to make a solid commitment.''

But Professor Hayes said other data had indicated the  divorce rate was growing for older people, which may be linked to the ''empty-nest phenomenon''.

Relationships Australia national vice-president Anne Hollonds said there was growing awareness about the negative impact of divorce, especially on children.

''Divorce brings with it its own problems. There has been more public discourse about divorce and its aftermath, and that may be leading to people trying harder once they're married,'' she said.

There was also greater demand for marriage counselling services, and people were seeking help earlier.