This is a drop from 23.4 per cent in the June 2016 quarter report, when these firms serviced 2.2 per cent of all SMSFs.

The proportion of firms servicing between 26 and 100 firms, on the other hand, increased from 49.5 per cent in June 2016 to 51.4 per cent, while firms servicing between 100 and 250 funds increased from 18.4 per cent to 20.6 per cent.

The proportion of major administrators, who service more than 1,000 funds, also saw a slight increase, rising from 1 per cent to 1.3 per cent. The major administrators grew their market share from 24.2 per cent of SMSFs at the end of June to 28.5 per cent at the end of December.

The median number of SMSFs per practice rose overall, increasing from 55 in June to 58 in December. The average number of SMSFs per practice increased from 115 to 122.

In terms of the assets held by SMSFs, listed shares still form the biggest proportion at 30 per cent, followed by cash at 22.2 per cent.

The top 20 domestic shares continue to make up a large proportion of the equities allocation in SMSFs, accounting for 51 per cent of the total SMSF domestic shares investment.

The report also revealed that SMSFs are not a threat to home buyers, with only 1 per cent of the residential properties owned by SMSFs in Australia, compared to 22 per cent owned by non-SMSF investors and 68 per cent held by owner-occupiers. 

That SMSF market share of residential property represents about $64 billion of the $6.7 trillion estimated value of the total residential market.

***Editor's note: This story has been updated***