The 2015 and 2017 general elections were the most volatile in modern times

% of voters choosing a different party from the previous election

43%

40%

30

33%

20

10

0

1966

1974

1992

2001

2015

1970

1979

1987

1997

2010

2017

43%

40%

30

33%

20

10

0

1966

1970

1974

1979

1987

1992

1997

2001

2010

2015

2017