New Zealand: the series starts in 1914, and it was not called a CPI until 1949
New Zealand's price data reaches back further than the series does. Food and rent were collected from 1891 and a wider set from 1907, but only for the four main centres. 1914 is where collection widened to 25 towns with population weights, and that is the point from which a national figure means anything.
The name came much later. What ran from 1914 to 1949 was a retail prices index; a 1948 committee recommended a new measure "to be known as the Consumers' Price Index", first published for the June quarter of 1949. The method changed again in 1974, from a consumption basis to an expenditure basis. So a long New Zealand conversion crosses two redefinitions as well as a lot of inflation.
One practical limitation: New Zealand's CPI is quarterly, not monthly, and still is. A monthly index has been announced, with the first official release due in July 2027.
Decimalisation on 10 July 1967
New Zealand went decimal on DC Day, 10 July 1967, at two dollars to the pound. So ten shillings became one dollar and a shilling became ten cents.
Because the ratio was fixed, the index chains through without a break, but an amount remembered in pounds, shillings and pence has to be converted before you enter it. Note this is the same 2:1 ratio Australia used in 1966, which makes the two easy to confuse with the British pound, where decimalisation changed nothing about the unit itself.
1987, not 1980, holds the peak
New Zealand inflation is usually remembered as peaking around 1980. The quarterly record actually belongs to the June 1987 quarter at 18.94%, with March 1980 close behind at 18.38%. On annual averages, 1980 leads at 17.15%.
The gap between those two dates is itself the story. Muldoon's wage and price freeze of 1982-84 pushed the annual average down to 7.34% and 6.17%, then it rebounded to 15.42% in 1985 once the controls came off: suppressed, not cured. New Zealand went on to become the first country to adopt formal inflation targeting, under the Reserve Bank Act effective February 1990. For contrast, the recent peak was 7.3% in the June 2022 quarter, described at the time as the largest annual rise since 1990.