Both annual instruction time and the length of compulsory education have an impact on the total duration of instruction over the course of compulsory education. In some countries, where compulsory education is shorter, students could face a heavier annual workload to meet the country’s statutory requirements. In other countries the workload is distributed evenly over more years. This indicator focuses on compulsory education at primary and lower secondary levels (in public institutions). However, 25 OECD and partner countries have at least one year of compulsory pre-primary education, so the starting age for compulsory education is younger than the starting age for primary education (see Figure X3.D1.1 in https://doi.org/10.1787/d7f76adc-en(OECD, 2023[2]), for more details on the number of years of compulsory education). Moreover, in around three-fifths of countries and other participants with available data, compulsory full-time education extends into at least one year of upper secondary education (Table D1.1). In most countries a large majority of students remain enrolled after the end of compulsory education (see Indicator B1).