The number of instances of "efficiency," peaks around 1920 and then falls (although it rebounds and keeps fairly steady). AThe 1970s are the period when flexible accumulation starts to replace Fordism. AOn the other hand, "productivity" is pretty non-existent, starts to increase around 1960 and peaks a little after 1980 and then drops down again. AAgain, this seems to vaguely conform to the Fordism to flexible accumulation shift.