Market monetarists generally favor a monetary regime that keeps some measure of nominal spending on output growing at a slow steady rate. Keeping nominal GDP growing at a slow stead rate is the most common approach. However, there are occasional mentions of per capita nominal GDP or even nominal GDP per member of the working age population.
The basic idea is that if there are more people, and in particular, a larger labor force, then the productive capacity of the economy will be larger, and so more spending on output would be appropriate. Or, alternatively, with a larger population, and in
particular, a larger labor force, keeping nominal income per worker growing at a slow, steady rate will be more consistent with maintaining full employment of labor.
Per capita nominal GDP is relatively easy to construct. It is also possible to calculate nominal GDP for the civilian eligible population, which is everyone over 16, not in the military, prison, nursing homes, or hospitals. Unfortunately, that includes all retirees. Still, it is possible to get the eligible population between 20 and 64. I had to add up the 20-24, 25-54, and 55-64 groups to find it. So, I found nominal GDP per person 25-54 too.
The trend growth rate for nominal GDP is 5.4% from 1985 to 2008. For all of the rest, the trend growth rates are very similar. For per capita GDP is is 4.26% and for the others it is 4.19%. It is hard to see much difference, though presumably, the reason to go with one of the other figures is to be prepared large shifts in the total population or shifts in the age composition of the population.