Early Childhood OECD figures

A new UNICEF report out shows that Australia is ranked 3rd last, only gaining 2 out of 10 assessable criteria. Some of the criteria looks a little odd, like 1% GDP on ECS. Why would the amount a country spends on early childhood be a criteria? How does that take into account stay-home moms? In fact the majority of benchmarks indicate that you should be using childcare. What about a mentor / student ratio of 1:2 as it is in our home?