In theory, you are correct. In practice, in a city or area with different valuations it may vary.

For example, in my city, 70% of households rent and half of those are in the hood. Bad neighborhood valuations are essentially a factor of Section 8 prevailing rent, and many properties fall off (as they stop meeting HUD standards) and get abandoned as they decay, because slumlords.

The effect is that in a good neighborhood, your pro rata share of the levy always climbs, even without an increase in value.