It's a change of voting system. We can see the same in Germany and in other countries that have mixed member systems. It's far more difficult for women and other minorities to get elected under first past the post in single-member districts than it is under the party list.
In single-member districts, the people who are recruiting candidates only pick one candidate for their riding or for their constituency, so they might well go for a safe choice, which is often seen as a candidate who might have experience in a particular way or fits the mould of the politician. Under a party list, you have basically a range of different candidates. You want a balance. You might want to balance by class or by language or by gender or by ethnicity, but essentially when you're selecting a party list, you don't want to discriminate against any group, because you might have a loss of popularity, a loss of votes.
The way that the systems work means that essentially—and we've known this since the 1980s—proportional representation has the strongest representation for women overall. Under the mixed member system, women get in through the party list. Under the first past the post, it becomes more difficult at the selection or recruitment stage for women to get selected, and therefore to get elected.