Mean data from Pitt (1935). From Table 4(5.14.2) of Wyszecki & Stiles (1982).
Though a standard data set, these data should be used with some caution. First, they may be subject to a wavelength-dependent calibration error. Second, since they were obtained by brightness matching, they may be influenced by short-wavelength sensitive cones at short wavelengths
Pitt, F. H. G. (1935). Characteristics of dichromatic vision. Medical Research Council Special Report Series, No. 200. London: His Majesty's Stationery Office.
Wyszecki, G., & Stiles, W. S. (1982a). Color Science (2nd ed.). New York: Wiley.