Complex sentence: While ratings were not as high as previous seasons, the series was still drawing respectable audiences, including a season average of 2 million viewers in Australia, half of them falling into the 18--49 demographic.
Split into simpler sentences: While ratings were not as high as previous seasons, the series was still drawing an audience of a respectable size. It had a season average of 2 million viewers in Australia, half of them in the 18--49 demographic.