Interesting.
I expected Dravid's to be in 50s.
Ponting's numbers are amazing. I have seen him playing great innings against new ball but I couldn't be decisive in my opinion because of him being covered by Langer, Slater and Hayden. Ponting's achievements sometimes go under-appreciated as compared to other great batsmen because of him playing in a team full of match-winners.
Just found Sachin's number's breakdown in different countries
These are upto 2009. He scored 5 overseas centuries after than and only one of them while coming at scoreboard showing less than 50, his Cape Town century. So I guess, averages wouldn't have changed much by the end of his career, except in case of South Africa.