I don't know the %, but in Aus auto is far more common than manual by a big margin. It seems exactly the reverse in UK. I notice this each year on my annual visit to my sister in Worthing when I have to pay extra to hire an auto car. When I was learning to drive in the UK, an auto box was an expensive add-on, usually only on cars 2.0L and above and the fuel consumption was always higher on auto.
The auto technology has improved and costs and consumption are down and yet it is still not as widespread in the UK as some other places - anyone know why? If this is off-topic, perhaps an admin could move it to a separate thread - thanks.