As of the second quarter of 2021, the INCOSE Certification Program has over 3800 SEPs, with approximately 2/3 from North America, primarily the United States. Outside the US, the leading countries with SEPs are the UK, Germany, Australia, Turkey, France, Italy, and Sweden. All of these countries have 100 or more SEPs.
Employers with the most SEPs are Northrop Grumman Corporation, Lockheed Martin, Booz Allen Hamilton, SAIC, Airbus, and Thales. They are followed by other large defense and aerospace companies.
The Certification Program posts a presentation of SEP statistics on the INCOSE website, here: https://www.incose.org/systems-engineering-certification/SEP-Learn-and-share