Impact Factor

... since 1975

Source: Journal Citation Reports® (Clarivate Analytics)

Year Impact Factor   Year Impact Factor   Year Impact Factor
1975 0.549   1992 0.403   2009 0.805 (0.959)
1976 0.607   1993 0.413   2010 0.713 (0.936)
1977 0.762   1994 0.625   2011 0.763 (0.854)
1978 0.618   1995 0.451   2012 0.614 (0.661)
1979 0.587   1996 0.595   2013 0.556 (0.667)
1980 0.389   1997 0.836   2014 0.728 (0.751)
1981 0.397   1998 0.697   2015 0.732 (0.716)
1982 0.555   1999 0.533   2016 0.586 (0.832)
1983 0.484   2000 0.701   2017 0.705 (0.861)
1984 0.545   2001 0.571   2018 0.731 (0.978)
1985 0.657   2002 0.722   2019 0.812 (0.879)
1986 0.756   2003 0.729   2020 0.887 (0.939)
1987 0.565   2004 0.924   2021 0.659 (1.000)
1988 0.444   2005 0.936   2022 0.3 (0.8)
1989 0.405   2006 0.778   2023 0.7 (0.9)
1990 0.752   2007 0.606   2024 0.9 (0.7)
1991 0.611   2008 0.831 (1.000)      

Note: since 2008, 5-year Impact Factors have also been listed (in parentheses)