XKCD comic 1007, "sustainable", has indicated that the frequency of the word "sustainable" has undergone significant growth. According to explain XKCD, it has gone from 0.000005% in 1960 to approximately 0.003% in 2012 - an increase in almost three orders of magnitude in half a century.
Have any other words experienced a sustained frequency growth greater than that?
- Relative growth, not absolute growth: the word "a" going from 1.4% to 1.5% is a large absolute growth, but very small relative growth.
- A non-trivial frequency at the end of the growth: "aimag" going from essentially zero before 1970 to 0.0000035% in 1999 isn't that significant. An ending frequency of at least 0.0001%, or preferably greater than 0.001%, would be good.
- Having a growth rate (measured over a period of at least two years) greater than that of "sustainable"'s half century average.