Have you seen the price difference for narrow and wide rim?

Follow collectors, do me yet another favor and check the NGC population for the 1979 SBA dollars and look at narrow and wide rim SBA dollars. Is that a correct price for a narrow rim SBA?? I went on another website and they pretty much said that the narrow constituted for about 45% of the population, before they went wide rim. What is the real difference between the 1979P, they 1979 narrow, and the 1979 wide? The wide and narrow I understand, but where does the plain 'ol 1979P fit in?