Among children that have been at least four years in kindergarten only 15% scored low, compared to nearly 40% of children with only 0-2 years of experience. The availability of free core time (20 hours per week) increased the participation of minority-language children by 15% and led to better results on mapping tests in the first and second grade compared to areas with no intervention (i.e. free core time). However, private business and non-profit organisations contribute to the cost of pre-primary education in a small number of countries.