Google index frequency

I just checked on Google Webmaster tools, and see:

"Googlebot last successfully accessed your home page on Dec 9, 2006."

How often does Google tend to crawl a site? How important is this?
FB

Crawling is periodic. I would not be concerned.

Thanks Joe. Do sites start getting crawled more frequently as they get better ranking? I enjoy learning about this stuff (I'm self-taught).

Thanks again for the forum. It's a great resource.
FB