Attitudes Regarding Marijuana Laws: Trends in 12th Graders

(Entries are percentages)
  1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019   2018 -
2019
Change
  2014 -
2019
Change
Proportional
Change
  Peak year -
2019
Change
Proportional
Change
  Low year -
2019
Change
Proportional
Change
Legal 12th Grade 32.6 33.6 32.9 32.1 26.3 23.1 20.0 18.9 18.6 16.6 14.9 15.4 15.1 16.6 15.9 18.0 18.7 22.8 26.8 30.4 31.2 30.8 27.9 27.3 31.2 29.2 30.8 29.5 30.5 27.6 27.1 29.3 29.4 31.8 36.2 39.2 39.3 41.5 43.4 42.4 44.7 48.9 48.2 50.7 | 2.5 | 7.3*** 16.8 | 0.0 0.0 | 0.0 0.0
Minor violation 12th Grade 29.0 31.4 30.2 30.1 30.9 29.3 28.2 26.3 23.6 25.7 25.9 24.6 21.9 18.9 17.4 19.2 18.0 18.7 19.0 18.0 21.0 20.7 24.3 23.7 23.4 24.5 24.2 25.8 26.5 27.7 27.6 27.8 30.0 28.9 28.6 26.9 26.8 25.0 24.6 27.4 28.5 25.9 27.0 24.9 | -2.1 | 0.3 1.1 | -6.5*** -20.7 | 7.5*** 43.2
Crime 12th Grade 25.4 21.7 22.2 24.0 26.4 32.1 34.7 36.7 40.6 40.8 42.5 45.3 49.2 50.0 53.2 48.6 47.6 43.4 39.4 37.3 33.8 34.0 32.6 32.5 30.2 31.1 29.1 29.8 28.4 29.7 31.7 30.2 27.5 26.0 21.8 21.3 21.7 20.8 17.0 15.4 13.8 12.4 10.5 9.4 | -1.1 | -7.6*** -44.6 | -43.8*** -82.2 | 0.0 0.0
Don't know 12th Grade 13.0 13.4 14.6 13.8 16.4 15.4 17.1 18.1 17.2 16.9 16.7 14.8 13.9 14.6 13.6 14.3 15.7 15.1 14.8 14.4 13.9 14.5 15.2 16.5 15.2 15.3 15.9 14.9 14.5 15.1 13.6 12.8 13.1 13.3 13.4 12.6 12.2 12.7 14.9 14.8 13.1 12.7 14.2 15.0 | 0.7 | 0.0 0.3 | -3.1* -17.4 | 2.7 22.4

Source: The Monitoring the Future study, the University of Michigan.
"There has been a great deal of public debate over whether marijuana use should be legal. Which of the following policies would you favor? Answer alternatives were:
(1) Using marijuana should be entirely legal, (2) It should be a minor violation like a parking ticket, but not a crime (3) It should be a crime, (4) Don't know.
The year with the highest percentage is noted in bold. The year with the lowest percentage after that peak is underlined.
For a table of Ns click here: Notes
*** = p < 0.001 ** = p < 0.01 * = p < 0.05