The year has nothing to do with SEO. In fact, this is a notice to the reader about the content's copyright. Indirectly there is a little bit of impact of the site's copyright year as it shows the active status on site even if you are not really updating the contents. If your site contains rare and time-sensitive content, readers might try checking your update status and confirm whether it might be outdated or not. In such cases, even if the content is fresh but the year is showing 2010, visitors might leave immediately which sends a bad ranking signal to search engines.