After their initial introduction in 1936, Incoterms were revised for the first time in 1957 and thereafter in 1967, 1976, 1980, 1990 and 2000. This appears to suggest that, in recent times, Incoterms have been revised at ten-year intervals. This, however, is a false impression. It is merely a coincidence that the last three revisions are separated by two ten-year periods. Indeed, the main purpose of Incoterms is to reflect international commercial practice. Needless to say, commercial practice does not change at a set interval.
Jan Ramberg, INCOTERMS 2010, 29 Penn St. Int'l L. Rev. 415 (2011).