The following categories refer to the highest level of schooling completed. Questions relating to educational attainment were changed in 1990, to better capture the relationship between educational attainment and labour market outcomes. Because this introduced a break in the education series, this table only contains data from 1990 onwards. Beginning January 1990, data on primary and secondary education reflects the highest grade completed. This provides a more consistent measure for those who accelerate or fail a grade than did years of school. A question on high school graduation has also been added since it is generally believed that persons who have never completed their secondary education have greater difficulty competing in the labour market. With the new questions, any education that could be counted towards a degree, certificate or diploma from an educational institution is taken as postsecondary education. The change allows more persons into the postsecondary education category. For example, trades programs offered through apprenticeship, vocational schools or private trade schools do not always require high school graduation. Such education is now considered as postsecondary while only primary or secondary would have been recognized prior to 1990. Finally, more information is collected on the type of postsecondary education: 1) some postsecondary; 2) trades certificate or diploma from a vocational or apprenticeship training; 3) Non-university certificate or diploma from a community college, CEGEP or school of nursing; 4) University certificate below bachelors degree; 5) Bachelors degree; and 6) University degree or certificate above bachelors degree.