Doping per year
Below is an overview for every Grand Tour, how many riders joined that were once penalized for using doping, or confessed to using doping. It does not mean that the doping was during that Grand Tour.
I focused on the Tour de France, so the overviews for Giro and Vuelta are less complete, and their numbers are higher.
| Year | Dopers | Total | Percentage |
|---|---|---|---|
| 1968 | 26 | 110 | 23% |
| 1969 | 48 | 130 | 36% |
| 1970 | 45 | 150 | 30% |
| 1971 | 47 | 130 | 36% |
| 1972 | 53 | 132 | 40% |
| 1973 | 50 | 132 | 37% |
| 1974 | 39 | 130 | 30% |
| 1975 | 41 | 140 | 29% |
| 1976 | 37 | 130 | 28% |
| 1977 | 36 | 100 | 36% |
| 1978 | 39 | 110 | 35% |
| 1979 | 33 | 150 | 22% |
| 1980 | 38 | 130 | 29% |
| 1981 | 47 | 150 | 31% |
| 1982 | 46 | 170 | 27% |
| 1983 | 42 | 140 | 30% |
| 1984 | 47 | 170 | 27% |
| 1985 | 40 | 180 | 22% |
| 1986 | 43 | 210 | 20% |
| 1987 | 46 | 207 | 22% |
| 1988 | 41 | 198 | 20% |
| 1989 | 39 | 198 | 19% |
| 1990 | 45 | 198 | 22% |
| 1991 | 42 | 198 | 21% |
| 1992 | 55 | 198 | 27% |
| 1993 | 50 | 180 | 27% |
| 1994 | 57 | 189 | 30% |
| 1995 | 54 | 189 | 28% |
| 1996 | 62 | 198 | 31% |
| 1997 | 63 | 198 | 31% |
| 1998 | 66 | 189 | 34% |
| 1999 | 51 | 180 | 28% |
| 2000 | 60 | 180 | 33% |
| 2001 | 57 | 189 | 30% |
| 2002 | 57 | 189 | 30% |
| 2003 | 54 | 198 | 27% |
| 2004 | 55 | 189 | 29% |
| 2005 | 51 | 189 | 26% |
| 2006 | 49 | 180 | 27% |
| 2007 | 47 | 189 | 24% |
| 2008 | 32 | 180 | 17% |
| 2009 | 26 | 180 | 14% |
| 2010 | 38 | 198 | 19% |
| 2011 | 31 | 198 | 15% |
| 2012 | 34 | 198 | 17% |
| 2013 | 15 | 198 | 7% |
| 2014 | 13 | 198 | 6% |
| 2015 | 15 | 198 | 7% |
| 2016 | 9 | 198 | 4% |
| 2017 | 8 | 198 | 4% |
| 2018 | 7 | 176 | 3% |
| 2019 | 6 | 176 | 3% |
| 2020 | 3 | 176 | 1% |
| 2021 | 3 | 184 | 1% |
| 2022 | 0 | 176 | 0% |
| 2023 | 3 | 176 | 1% |
| 2024 | 2 | 176 | 1% |
| 2025 | 3 | 184 | 1% |
| Year | Dopers | Total | Percentage |
|---|---|---|---|
| 1968 | 25 | 130 | 19% |
| 1969 | 12 | 130 | 9% |
| 1970 | 17 | 130 | 13% |
| 1971 | 11 | 100 | 11% |
| 1972 | 15 | 100 | 15% |
| 1973 | 16 | 140 | 11% |
| 1974 | 12 | 140 | 8% |
| 1975 | 10 | 100 | 10% |
| 1976 | 20 | 120 | 16% |
| 1977 | 17 | 140 | 12% |
| 1978 | 13 | 130 | 10% |
| 1979 | 13 | 140 | 9% |
| 1980 | 13 | 130 | 10% |
| 1981 | 13 | 130 | 10% |
| 1982 | 16 | 162 | 9% |
| 1983 | 18 | 162 | 11% |
| 1984 | 19 | 171 | 11% |
| 1985 | 17 | 180 | 9% |
| 1986 | 19 | 171 | 11% |
| 1987 | 27 | 180 | 15% |
| 1988 | 22 | 180 | 12% |
| 1989 | 28 | 198 | 14% |
| 1990 | 33 | 198 | 16% |
| 1991 | 24 | 180 | 13% |
| 1992 | 32 | 180 | 17% |
| 1993 | 36 | 180 | 20% |
| 1994 | 30 | 153 | 19% |
| 1995 | 41 | 198 | 20% |
| 1996 | 31 | 162 | 19% |
| 1997 | 32 | 180 | 17% |
| 1998 | 33 | 162 | 20% |
| 1999 | 36 | 162 | 22% |
| 2000 | 45 | 180 | 25% |
| 2001 | 49 | 180 | 27% |
| 2002 | 44 | 198 | 22% |
| 2003 | 34 | 171 | 19% |
| 2004 | 24 | 171 | 14% |
| 2005 | 46 | 198 | 23% |
| 2006 | 34 | 198 | 17% |
| 2007 | 28 | 198 | 14% |
| 2008 | 31 | 198 | 15% |
| 2009 | 23 | 198 | 11% |
| 2010 | 18 | 198 | 9% |
| 2011 | 24 | 207 | 11% |
| 2012 | 17 | 198 | 8% |
| 2013 | 29 | 207 | 14% |
| 2014 | 24 | 198 | 12% |
| 2015 | 18 | 198 | 9% |
| 2016 | 13 | 198 | 6% |
| 2017 | 11 | 198 | 5% |
| 2018 | 4 | 176 | 2% |
| 2019 | 6 | 176 | 3% |
| 2020 | 6 | 176 | 3% |
| 2021 | 3 | 184 | 1% |
| 2022 | 5 | 176 | 2% |
| 2023 | 3 | 176 | 1% |
| 2024 | 2 | 176 | 1% |
| 2025 | 2 | 184 | 1% |
| Year | Dopers | Total | Percentage |
|---|---|---|---|
| 1968 | 15 | 90 | 16% |
| 1969 | 21 | 100 | 21% |
| 1970 | 26 | 110 | 23% |
| 1971 | 35 | 110 | 31% |
| 1972 | 27 | 100 | 27% |
| 1973 | 23 | 80 | 28% |
| 1974 | 26 | 90 | 28% |
| 1975 | 20 | 90 | 22% |
| 1976 | 23 | 100 | 23% |
| 1977 | 17 | 70 | 24% |
| 1978 | 15 | 100 | 15% |
| 1979 | 21 | 90 | 23% |
| 1980 | 18 | 110 | 16% |
| 1981 | 19 | 90 | 21% |
| 1982 | 21 | 100 | 21% |
| 1983 | 17 | 100 | 17% |
| 1984 | 16 | 130 | 12% |
| 1985 | 25 | 169 | 14% |
| 1986 | 27 | 170 | 15% |
| 1987 | 26 | 180 | 14% |
| 1988 | 29 | 180 | 16% |
| 1989 | 20 | 189 | 10% |
| 1990 | 22 | 198 | 11% |
| 1991 | 33 | 198 | 16% |
| 1992 | 31 | 189 | 16% |
| 1993 | 21 | 169 | 12% |
| 1994 | 27 | 169 | 15% |
| 1995 | 38 | 180 | 21% |
| 1996 | 33 | 180 | 18% |
| 1997 | 42 | 198 | 21% |
| 1998 | 48 | 198 | 24% |
| 1999 | 45 | 189 | 23% |
| 2000 | 41 | 180 | 22% |
| 2001 | 44 | 189 | 23% |
| 2002 | 45 | 207 | 21% |
| 2003 | 44 | 198 | 22% |
| 2004 | 49 | 189 | 25% |
| 2005 | 37 | 198 | 18% |
| 2006 | 38 | 189 | 20% |
| 2007 | 27 | 189 | 14% |
| 2008 | 21 | 171 | 12% |
| 2009 | 25 | 198 | 12% |
| 2010 | 25 | 198 | 12% |
| 2011 | 18 | 198 | 9% |
| 2012 | 14 | 198 | 7% |
| 2013 | 15 | 198 | 7% |
| 2014 | 14 | 198 | 7% |
| 2015 | 9 | 198 | 4% |
| 2016 | 8 | 198 | 4% |
| 2017 | 10 | 198 | 5% |
| 2018 | 6 | 176 | 3% |
| 2019 | 4 | 176 | 2% |
| 2020 | 3 | 176 | 1% |
| 2021 | 2 | 184 | 1% |
| 2022 | 2 | 183 | 1% |
| 2023 | 1 | 176 | 0% |
| 2024 | 1 | 176 | 0% |
| 2025 | 1 | 184 | 0% |
The percentage in the Tour has for many years been around twenty-five percent, except in the recent decade. It could mean that riders have become more clean. However, I suspect that the percentage of "cheaters" did not significantly change, and we will still get confessions from riders of the most recent decade.
