Mr. Nicholas Tarrant:

The setting of the tariffs is an annual process. It is done every year. The tariff model is updated just like the DUoS model.

In response to the Senator's earlier question, and as we outlined in our opening statement, this was a systems error around change control. As we look back on it now, there was a change made here and the testing that was done, and the realisation about how it would impact on tariffs, was not fully understood in the way it was implemented. The calculation in the model is relatively deep in the model. It is not obvious. The model was updated every year. The reality is, when we look back - and the review that was commenced in 2021 uncovered this - it was not uncovered so there is no particular answer I can give as to exactly why that was not the case. I cannot comment in the absence of finding it because it was not. When one looks at the facts of what happened here, it was changed in the second year of implementation. That worked its way all the way up to 2021 when it was reviewed as part of the work sponsored by CRU and, ultimately, it was discovered then. As soon as it was discovered, we brought it to the attention of the CRU, set out the calculation as we saw it whereby it was not a fixed amount and it was changing based on the variables. That is as much as I can say about the matter.