Digital Strategist and author Basia Coulter polls industry colleagues and everyday web users for preferences and latest practices. Well researched and written article should be of interest to UX people as well as website owners: https://www.caktusgroup.com/blog/2017/03/01/opening-external-links-same-tab-or-new/

When I first started building websites the convention was to have links open in the same window and site users would use the back button to navigate back to the page which contained the link. But with the advent of tabbed browsing and client anxiety about users leaving their site and never returning I generally code links to open in a new window or tab. My preference is for websites that handle opening external links in this manner as well.

If you have a preference about what happens when users click outgoing links on your website be sure to let us know. We can code links either way, but we would recommend choosing one method or the other so the user of the site knows what to expect prior to clicking on those links.