Poland also had one of the largest increases in enrolment in education at ages 3 and 4 between 2005 and 2013 among countries with available data, although it remains below the OECD average. About 52% of 3-year-olds and 66% of 4-year-olds are enrolled in education, compared to an OECD average of 74% and 88%, respectively. Among OECD countries, Poland had a higher ratio of children to teaching staff in pre-primary education: 16, compared to 14 on average in other OECD countries.