Do you have community pages on your website? Stats show that deindexing these can help boost your rankings. Britney Muller of Moz recently deindexed 75% of Moz’s website the majority of the types of pages were community profile pages.
When searching 'moz.com' in Google search, 56% of the search results were community pages - thousands of pages that needed to deindexed.
Instantly, organic traffic and rankings went up.
Take a read of this article by Kissmetrics to find out other ways you can deindex irrelevant pages that may be hurting your search rankings.
Why removing pages from search results can boost traffic You might think that it isn’t possible to over-optimize your site. But it is. Too much SEO can ruin your site’s ability to rank high. Don’t go overboard. There are many different occasions where you may need (or want) to exclude a web page (or at least a portion of it) from search engine indexing and crawling. The obvious reason is to prevent duplicate content from being indexed. Duplicate content refers to there being more than one version of one of your web pages. For example, one might be a printer-friendly version while the other is not.