Murtaza Umair provides guidance:
Keeping your database up to date with the latest PostgreSQL release is vital in maintaining the security of your database. Once every year, PostgreSQL comes out with a new release, which includes new features, security enhancements, and performance improvements. Each major release is supported for five years, during which PostgreSQL releases quarterly minor updates to fix bugs and patch security issues. The schedule for new updates and more information is given on PostgreSQL’s website, at https://www.postgresql.org/developer/roadmap/.
Nothing in this is earth-shattering but it is a solid overview.