Electronic cigarettes (e-cigarettes): Trends in Harmfulness as Perceived by 8th, 10th, and 12th Graders

(Percentages saying great risk)
  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   2016 -
2017
Change
  2012 -
2017
Change
Proportional
Change
  Peak year -
2017
Change
Proportional
Change
  Low year -
2017
Change
Proportional
Change
Using regularly 8th Grade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.5 18.5 21.3 20.3 | -1.0 | . . | -1.0 -4.6 | 0.0 0.0
  10th Grade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.1 17.0 19.1 19.4 | 0.3 | . . | 0.0 0.0 | 0.0 0.0
  12th Grade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.2 16.2 18.2 16.1 | -2.1 | . . | -2.1 -11.8 | 0.0 0.0

Source: The Monitoring the Future study, the University of Michigan.
Answer alternatives were: (1) No risk, (2) Slight risk, (3) Moderate risk, (4) Great risk, and (5) Can't say, drug unfamiliar.
For 8th and 10th graders data based on two thirds of N indicated on the table of Ns.
For 12th graders data based on two of six forms; N is two times the N indicated
The year with the highest percentage of those saying great risk 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