The number of links that are nofollow. NoFollow backlinks carry zero SEO value, however, it is advised to keep a healthy dofollow/nofollow ratio.
NoFollow backlinks are still valuable as they may not carry SEO value but they can result in getting you traffic which is also very important for your business.
On September 10, 2019, Google announced a big change. Instead of ignoring links that were deemed nofollow, Google will now start to view nofollow links as “hints.” The search engine can use this hint to determine whether or not the link should be followed and considered in the page’s ability to rank.
Well known sites are giving nofollow links as below: