Taken in the context of The European Fine Art Foundation's (TEFAF) 2012 report, which values the global art market at just over €46bn, it means that BADA members account for around 2.5% of all world antiques trade by value. BADA secretary general Mark Dodgson said: "The proportion of global turnover that this represents confirms our view that London is still the greatest centre for art and antiques in the world."
With responses from half of the association's 324 trading members and spot checks with Companies House to ensure that published figures match responses, the BADA can argue that their survey is robust.
As with the LAPADA survey published last week, US clients are the most important international buyers for BADA dealers, accounting for 26% of all exports by value.
Where the two association reports differ widely is in internet sales. While LAPADA reported 19% of all sales conducted online, BADA members registered 6%, although at least two members reported that the internet accounted for 80% of their sales.
However, such high percentages tend to be among dealers whose annual turnovers fall at the lower end of the earnings spectrum among members. What the difference between BADA and LAPADA members is in terms of exact internet sales by value is also not clear, so it is possible that in real terms there is less of a disparity than might first appear.
Overall, the BADA survey showed that things had got slightly better for members during 2011, with 37% reporting improved sales compared to 35% the previous year. There was also a smaller number - 27% compared to 30% - who had seen sales decline.
Exports were slightly up, representing 52% of all sales, but overseas buyers are far more important in London and the South East, where they account for 55% of all sales, than in the rest of the UK, where they make up only 18%. London dealers fared better than the rest when it came to improving sales, with 45% reporting an increase compared to only 17% in the North. The BADA believe that this may be because the majority of members in the north run smaller, traditional art and antique shops and galleries, with less international trade, although a number of them do stand at fairs in London and overseas.
These regional trends appear to follow findings that dealers trading at the top end, with turnovers in the millions of pounds, are faring better than the rest.
In Greater London, 20% of members have a turnover of £5m or more, compared to 18% the previous year, and 45% of members in Greater London enjoyed sales of at least £1m, just up on the numbers who did in 2010.
No individual members in Scotland, the Eastern or Southern regions saw sales over £1m for the current period.
The turnover bands enjoyed by most members were £100,000-500,000 (34%) and £500,000-1m (25%). At the extremes, 8% turn over less than £100,000 and 3% over £20m.
Assessing different specialist disciplines, the survey concluded: "It is apparent that, as in previous years, a dealer's sales are generally higher where the unit cost of their stock is also relatively high."
This was clearly reflected in comparisons between ceramics and glass dealers (excluding Asian ceramics), where 73% had sales of less than £500,000 and none took more than £2m, and silver and jewellery, where 87% enjoyed turnovers of more than £500,000, with some taking tens of millions of pounds.
The unit price factor showed up starkly in furniture sales, too. Furniture dealers with sales above £1m rose from 20% in 2010 to 26% in 2011.
Almost all Oriental dealers saw a rise in turnover (94%), while the only discipline which saw a marked decline compared to 2010 was ceramics and glass.
Shops and galleries are still the trade's mainstay, accounting for 51% of all sales by value, with fairs coming in second at 29%. Exhibitions contribute 7% of sales, followed by the internet at 6%. Sales by auction (4%) and from home (3%) account for the remainder.
There is a bigger diversity when it comes to sourcing stock. Just in the lead is private UK sources, accounting for 24%, ahead of UK auctions at 23%. Buying from other dealers adds another 18%, while overseas auctions bring in 12%. Overseas dealers and private clients account for another 10% each.
Looking at staffing profiles, 23% of members trade alone, with another 26% employing one other. A further 20% employ two people in addition to themselves.
No more than 18% of members employ a total of more than five people, although 2% employ more than 40 each.