Rt Hon JACINDA ARDERN: We have a set of criteria that we've been using continuously throughout COVID-19 and movements around alert levels. It is not based solely on whether or not we have single cases or, indeed, whether or not a case emerges; it's all about whether or not we can identify the source of it and whether there are high-risk exposure events. So, to give you a specific example, the decision to go into level 3 in the most recent outbreak was because we had an individual where we could not immediately identify the source, but more importantly, perhaps, a high number of significant exposure events that we considered to be high risk, given the sheer number of people who may have come in contact with the case.