The RMS cycle count shows steady increases year by year for the Habour Bridge, from 907 in 2007 up to 1,944 per day in 2012. The City of Sydney count shows similar numbers coming off the Harbour Bridge. Similarly Anzac Parade shows a steady increase from 354 in 2007 up to 993 per day in 2012.
In contrast the numbers from the RMS on the Anzac Bridge are
- 2007: 840
I have sent an email along these lines to the RMS & to the City of Sydney, will let you know if I manage to find out whether this some problem with the count or some other explanation.