Ideas for Planetary stats in a Space 4x game

		Habs	 	Industry 		Research 		Total
Area		10(+2)/100(+1)	20(+4)/300(+3) 		25(+8)/500(+4)		600(+8)/1600
Efficiency	1%		20%			10%
Population			2(+1)/4(+1)		2(+1)/4(+1)		4(+2)/10(+0)
Morale		90%
Spending	0%		40%			60%

Planetary Development 100% Ship 0%

Explanation:
The numbers in brackets are how much the quantity next to them increases by in a year (or equivalent period).

For Area the first number before the slash shows the current area of the planet being used and the second shows the total available developed area in each category. The first number under total area is the sum of the second numbers under Habs, Industry and Research and the rate in brackets is the sum of their rates.

The Efficiency shows how well the area is being utilized. Habs are used as living space and to grow food, Industry is used to build stuff (all the rates except population are a function of it) and Research to research more tech. You can increase the rates via. various techs and raising morale, and the total usable area on the planet (1600 in the example above) can be raised with rare techs.

For population the second number under Habs and Research is how many units of population are needed to work the factories/labs and the first is the currently available population. The second number under total population is the population that can comfortably live in the currently available hab area at the current efficiency, and the first number is the current population. The current population can and will go over the max if you don't have enough habs, but morale will drop due to overcrowding. The population rate depends on how much space you have available, and eventually the population will cap out. You can make it cap at a lower value, decrease (or even increase) the population growth and/or reduce the effect of overcrowding on morale with the right techs. You can also relocate the extra population to other planets that have enough living space. Note that if you have too many people you don't actually get more industry or research (there's only so many jobs!).

Morale affects industry and research output. Overcrowding reduces it, and actions during war can increase or decrease it.

The player chooses how much of the total industrial output to allocate towards planetary development, and the rest goes to building ships. The spending is further divided among Habs, Industry and Research development, which is used to increase the amount of land available for each.