I also gave the example of the Netherlands; they do not have a legislative mandate, but they began to work in that way in 1986. However, I would say that it is not the best example, given that they have a parliamentary system that is quite different from ours.
In a country with 10 political parties, it is a little easier to come up with calculations, because everyone wants to do it. Only Australia has the legislative mandate to do so. By the way, it is interesting to note that they are presently in an election campaign and that the act is changed so that they have to report after the elections.