Is an addition or subtraction of 1% or 2% of an officer's work required to be performed in order to meet the volume of the duties required for the officer to perform the same amount of work?

"... An addition or subtraction in relation to the volume of the duties required to be performed by an officer, which does not substantially affect the primary duties of his office, is not such a change of duties as would prevent immediate effectiveness of legislation properly declared to be urgent." (20 Cal.2d at p. 37, 123 P.2d 488, italics added; see also People v. Robertson (1982) 33 Cal.3d 21, 47, 188 Cal.Rptr. 77, 655 P.2d 279.)