I have a site where user can create their profile page with their specific URL. Each specific URL will be available to public which means that it will also be ready for search engines too to crawl. Today I am getting today a minimum of 1000 new profile pages today and 10-40 pages getting indexed by Google in 24 hours. That is fine.Here is my problem: But already indexed pages are being again and again crawled by Google after some period of time. But that's actually not required and the site is now having 300000 - 400000 pages.So I don't want the search engine to be crawled for old profile pages again and again unless until there is new update and it is fine to crawl the new pages. Also i already using 410 redirection for the expired profile pages. It would be great if you suggest, so that Search engine focus for new profile pages only instead of old pages. 
How to control old indexed page crawling rate
seo;google;web crawlers;googlebot;crawl rate