The default frequency of visits is 1 page every minute

If you have set a crawl-delay then frequency of visits is 1 page per crawl-delay settings if crawl-delay is less than 1 minute

Pages already indexed updated a minimum of 90 days

Pages tagged as noindex updated a minimum of 180 days

Pages that contain a canonical link updated a minumum of 180 days

Home page updated every 14 days

Robots.txt updated every 7 days

Sitemaps updated every 90 days