Does every sold propertly show up on Domain's "SOLD" search? (it uses RPData right?)

Realestate.com.au's SOLD search appears to only show a few years of data. Domain seems to go back over a decade so I've been using that. I've been using it to get a sense of volume of sales over the last decade to try to get a sense of the likelihood an apartment in a group of 4 buildings I really like is likely to go on sale. Things seem pretty grim so far - 8 in the last 12 years. Tightly held. Is this representative of all the data? Is my reading of this as bad as it looks? Or do a lot of sales just not show up?

 

Corelogic caution that only RPData can be relied on as complete and spanning 20 years. No way will they dump 20 years of complete data on the web (even the NewsCorp owned Domain) when their business is built on selling data... and the more you pay the more you get. Domain may only show what they have listed eg Units 1-4, 6 and 10 and disregard others. ie excludes positives that are false for Domain.

 

Personal experience: sold our PPOR earlier this year privately. realestate.com.au has no knowledge that it was sold. You can only find it on domain if you specifically search the property address, even then the sale date is listed as unknown, only the month & year is shown. It doesn't show if you search for sold properties. So private sales are not showing.