 These differences between disciplines have been present for at least 40 years, and sparse earlier data suggests that they date back 70 years or more.Until recently, the evidence for grade inflation in the US has been sparse, largely anecdotal, and sometimes even contradictory; firm data on this issue was not abundant, nor was it easily attainable or amenable for analysis.National surveys in the 1990s generally showed rising grades at American colleges and universities, but a survey of college transcripts by a senior research analyst in the U.S. Department of Education found that grades declined slightly in the 1970s and 1980s.