Unfortunately, I do.
The IAI was picked at the time because it actually reflected wages. It was an attempt to provide an indicator that roughly approximated increases in wage levels. As this index is based on salary, it was simple as that.
At the most recent commission, the government did attempt to assert that CPI would be a more appropriate guard against inflation than the IAI. The commission recommended against that, and recommended that IAI be preserved. There has been a rough relationship over a number of years between the IAI and the CPI. Some years it's higher, some years it's lower, but if you look at the graph over time, it's roughly approximate. This year it was a loss, for sure. The CPI exceeded the IAI.