UK
October 1959 - October 1964: Conservative
October 1964 - June 1970:
Labour
June 1970 - March 1974
Conservative
March 1974 - May 1979
Labour
May 1979 - May 1997
Conservative
May 1997 - May 2010
Labour
May 2010 - May 2015
Conservative/Liberal Democrat Coalition
May 2015 - present
Conservative
You do not need to be a mathematical genius to see that, since the start of the 1960s, the right have been in power here for almost twice as long as the left have.
Obviously the UK isn’t the world; so the obvious other place to look, geopolitically speaking, is the US. Where the picture regarding power is of course more complicated, but the obvious place to start is with Presidents.
Presidents
[1960] Eisenhower (R)
1961-1963 Kennedy (D)
1963-1969 Johnson (D)
1969-1974 Nixon (R)
1974-1977 Ford (R)
1977-1981 Carter (D)
1981-1989 Reagan (R)
1989-1993 Bush (R)
1993-2001 Clinton (D)
2001-2009 W. Bush (R)
2009-2017 Obama (D)
2017-2021 Trump (R)
2021-now Biden (D)
So the Republicans have had 33 years & the Democrats around 29 years 10 months of the Presidency each since 1960. Fairly even. But the balancing act with the legislature (I’m not going to try to evaluate the third side of the triangle here!) does shift the picture somewhat. Nonetheless, it all arguably becomes moot when one considers that the Democrats are not, in fact, a left-wing party at all 🤷♀️
Personally I appreciate those crazy leftist notions that have persisted, like universal health care. I am very much enjoying my neither being dead nor having bankrupted my family with my wanton crippledom.