The history of changing PMs mid-term

Chris Hipkins taking over from Jacinda Ardern is the 8th time this has happened since WWII. The previous seven were:

1. 1957 – Holyoke from Holland 87 days before the election which they lost
2. 1972 – Marshall from Holyoake 306 days before the election which they lost
3. 1974 – Rowling from Kirk, 463 days before the election which they lost
4. 1989 – Palmer from Lange, 453 days before the election which they didn’t get to contest
5. 1990 – Moore from Palmer, 60 days before the election which they lost
6. 1998 – Shipley from Bolger, 733 days before the election which they lost
7. 2016 – English from Key, 319 days before the election which they lost

This is of course no guarantee that Hipkins will lose, but that the track record to date is not great.