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 2017 report:
There are currently 30,875 churches in the denomination (22,928 considered officially organized).
The Church of the Nazarene has 17,911 ordained elders, 858 ordained deacons, and 9,950 licensed ministers.
Information is based on reporting received from districts for assemblies held October 1, 2016, through September 30, 2017.