Verisign has released their latest quarterly Domain Name Industry Brief (.pdf file) covering the 2nd quarter of 2019. While Verisign is best known as the administrator of .com and .net domains, their quarterly briefs provide statistics   covering the entire universe of domain names. According to the latest brief, 2Q-2019 closed with approximately 354.7 million domain name registrations across all top-level domains (TLDs), an increase of approximately 14.9 million domains (representing a 4.4% jump) over the past year. 

The world's most popular extension, .com, continues to outperform the overall market. The number of registered .coms jumped 

approximately 6.9 million from the same point a year ago, an increase of 5.1% year over year. Verisign's .net also continue its trend of slow decline. The number of registered .nets slipped to about 13.6 million at the end of 2Q-2019, a drop of around a half million domains (representing a 3.5% decline).

In percentage terms, the category with the highest growth rate was the ccTLDs (country code domains). They ended 2Q-2019 with approximately158.7 million registrations, 8.9 million more than a year ago for a healthy 6% increase.

There hasn't been a lot of good news for new gTLDs lately but they posted a year over year upturn, gaining about 1.3 million registration (a 5.9% increase) that put their total registrations at approximately 23 million at the end of 2Q-2019. 

There is much more data in the complete Domain Name Industry Brief that you can access here.