Statistics are reported annually to the Church of the Nazarene General Board. These reports include comparisons with the previous year and the previous decade.
From the 2018 report:
There are currently 30,712 churches in the denomination (23,062 considered officially organized).
The Church of the Nazarene has 18,290 ordained elders, 1,002 ordained deacons, and 10,434 licensed ministers.
Information is based on reports received from districts for assemblies held 1 October 2017 through 30 September 2018.
The full, printable statistical report is available in English (PDF). The Statistical Comparisons Table is available in Português, Français, and Español.