childs_per_woman_per_year = d3.sort(
countries.map(country => {
const country_data = raw_data.filter(d => d.Entity == country);
const data = country_data.map((dd, i) => {
return {
date: new Date(Date.UTC(dd.Year, 0, 1)),
value: dd.Fertility_Rate
};
});
return {
country,
data
};
}),
s=> s.Entity
)