We need a weighted Big Mac Index

The Economist's Big Mac Index has been a fun way of comparing currencies' purchasing power relative to one standard ubiquitous good: the Big Mac.

Turns out standard isn't as standard as I'd have expected.

Americans get a lot more for their money than folks in the UK.

It looks like the NZ Big Mac gives you a bit more than the UK version, but a bit less than the US. 

Kiwis get 96.1% of a proper Big Mac, and Brits get only 83.6%. 

Update your Big Mac Index values accordingly.