Hon CHRIS HIPKINS (Minister of Education): In answer to the member's question, the work around schools has been looking specifically at a classroom environment and those classrooms that do or don't have natural ventilation. So no, that information was not available, but information around the benefits of natural airflow have been available from the beginning. It is one of the reasons why I've stood in this House many times over the last six months and explained to Opposition members who have been demanding to know why we haven't ordered more air cleaners that we haven't because they're not actually justified. 