I imagine it has others puzzled too, so here is a bit more on what (I think!) it means, and apologies for the delay in responding!
The figures - step one: overall mass attendance rates
In 2006, a census was done of those who attended Mass across four Sundays in May.
It found that 708, 618 people attended mass or a Sunday Assembly in the Absence of a Priest on average on those Sundays. Thanks to the official census, we know that in total there were 5, 126, 884 people claiming to be Catholics in 2006. Divide the first figure by the second and you will get 13.8%.
So on average, around 14% of Catholics turn up at Mass each week.
Step 2: By diocese
But of course the Mass attendance rates vary by diocese.
The Pastoral Projects Office of the ACBC hasn't, for some strange reason, at least as far as I can find, released the percentages by diocese.
But it has provided a table, in the recently released See I am doing a new thing. A report on the 2009 survey of Catholic Religious Institutes in Australia (the relevant table, which uses 2006 data, is on page 17), which, in conjunction with the National Sunday Mass Attendance Report, enables you to calculate these.
What the table I've been using (from the Report on Religious Life) actually provides is a comparison between the proportion of Catholics in Australia and the proportion of Mass goers in Australia.
Take a diocese like Broken Bay. It has 4.2% of Australia's Catholics located in it. So 4.2% of 15.1m adds up to 215,329 people.
It also has 4.2% of mass attendees. So that is 4.2% of those 708, 618 attenders across Australia, or around 29,761 people turning up to Mass each week in Broken Bay.
Divide 29,761 by 215, 329 and you get 13.8% - in other words, if you have the same proportion of Catholics as you have of Mass attendees then Mass attendance rates for the diocese are exactly on the national average.
What this means is that if the proportion of Catholics in the diocese is, like Sale 2% of all Australians, and the proportion of Mass attendees is only 1.7%, the proportion of Catholics going to Mass in the diocese is a lot lower than 13.8% (in fact around 11.7%). To see just what the proportion of Catholics who turn up at Mass each week at mass then, you have to do the arithmetic above. And I admit I've been a bit lazy (or short of time!) and haven't bothered to do the calculations for each diocese up until now.
But the results are quite interesting (if depressing), so here are a few.
Comparing the proportion of Catholics with the proportion of Mass attenders
Keep in mind though, that they are just different ways of presenting the same data. And that they are little old now. Do let me know if you think I've made an error though. Note also that I'm using the rounded percentages from public reports, so the figures are not exact).
Perth: 14.4% of Catholics attended Mass (diocese has 7.4% of all Catholics; 7.7% of Mass attenders)
Broome: 6.9% attend Mass (0.2% of Catholics; 0.1% of attenders)
Bunbury: 9.6% (1% of Catholics; 0.7% attenders)
Geraldton: 10.4% (0.4% of Catholics; 0.3% of attenders)
Wagga Wagga: 16.1%
Broken Bay: 13.8%
Port Pirie: 13.8%
I'll let you ponder further what these numbers really mean, although I have to say the Sydney (18.3%) vs Broome (6.9% comparison) is pretty stark. Of course, the clearest message is that five decades of the spirit of Vatican II have created a nation whose Catholics are mostly of the lapsed variety...
**I've added the most rest of the figures in and provided a more direct link to the report whose figures I'm using since some readers don't seem to have been able to locate it.
PS aCatholicas, I am not a 'conservative blogger' either politically or theologically as you would discover if you read this blog a little more closely. If you must label me, traditionalist committed to genuine renewal within the Church would be closer to the mark.