If the agent is both the selling agent and the listing agent, he/she will receive around 75% of the commission; the rest goes to the Agency.
If there is a different agent who sells the property to the listing agent, then they split the 75% commission.
Don't know where you got this statistic from, but across Australia it's around 35-50% of total commission for a beginner to above-average salesperson - the agency makes 50% or more normally; unless of course you're like Judy Goodger in Brisbane RW who I suspect would make around 80% commission.