Refers to the highest level of education successfully completed.
Higher education: higher vocational education (hbo) or university.
Secondary education: (an equivalent of) lower secondary general education (mavo), higher secondary general education (havo), pre-university education (vwo) or secondary vocational education (mbo).
Lower education: primary education or lower vocational education (lbo).
The percentages referred to in the text and the graph are corrected for age differences between the various groups.