This is a development key. The index is based on the cost per enrolled child in municipal preschool and the net cost deviation for preschool. The KPIs are normalised so that all municipalities’ values are placed on a scale from 0 to 100 where 0 is the worst (maximum cost) and 100 is best (minimum cost). To avoid excessive impact, the value is set to 0 for municipalities with values below percentile 2.5, and 100 for municipalities with values above percentile 97.5. For those municipalities that have data on both KPIs, the unweighted average is calculated, and then the mean is also normalised to a scale of 0 to 100 in the same way. The index is the normalised average. RKA’s calculations based on data from Statistics Sweden.