A moth's color is controlled by two alleles, G and g, at a single locus. G (gray) is dominant to g (white). A large population of moths was studied, and the frequency of the G allele in the population over time was documented, as shown in the figure below. In 1980 a random sample of 2,000 pupae was collected and moths were allowed to emerge. The figure shows a graph in the first quadrant. The horizontal axis is labeled time from 1960 to 1980 in five year increments with a tick mark at each increment. The vertical axis labeled frequency of G allele in population from zero to one in increments of point two with a tick mark at each increment.. The frequency of the g allele begins at zero point eight in 1960 and remains there until 1965. There is a decrease in frequency from 1965 to 1972 from zero point eight to zero point five. The frequency remains at zero point five from 1973 to 1980.

Assuming that the population was in Hardy-Weinberg equilibrium for the G locus, what was the frequency of allele G in the gray moths that emerged in 1980?