The Creative Commons has released State of the Commons 2017.
Here's an excerpt from the announcement:
People, projects, and programs make up the bulk of this year’s report, but the data also supports our vision of a more creative, open world. 1.4 billion works is 200 million more than last year, and that growth has accelerated compared to the previous two years. To provide concrete examples: The Metropolitan Museum released 375,000 pieces of content under CC0 in February 2017. PLOS counts 7,000 editorial board members and 70,000+ volunteer peer reviewers to release 200,000 pieces of content. Wikipedia, one of our closest allies and partner in the “Big Open”, hosts 42 million freely licensed pieces of content. Our search tool has responded to 1,500,000 queries, and our website has been visited 50,000,000 times. And that’s only a part of our impact.