Having 2% nationwide provides the most research points which clergy can provide, but research points (and other things) are also effected by literacy, for which the prime number of clergy (fastest literacy gain) is at 4% per province.
Bureaucrats have ideal efficiency at 1% per state (state admin.) and nationwide (admin. efficiency), non-colonial. State administration provides crime-fighting and National Focus efficiency, national admin. efficiency provides tariff and tax efficiency (slider vs. actual). That 1% rises when you institute social reforms such as healthcare.
Does National Admin efficiency affect the speed of colinisation?