The five Chinese teachers featured in the BBC documentary Are Our Kids Tough Enough? Chinese School. The documentary triggered a heated debate on British and Chinese education methods.

SHANGHAI - Shanghai middle school teachers are among the world's most qualified, according to a survey by the Organization for Economic Cooperation and Development (OECD).

OECD surveyed nearly 4,000 Shanghai teachers from 199 junior middle schools in 2015 along with teachers from 37 other countries and regions.

Shanghai's education impressed the world after students of the city won first place in the Program for International Student Assessment, the OECD's math, science and reading tests of students from dozens of countries, in 2009 and 2012.

Some 98.5 percent of the polled Shanghai teachers have bachelor's degrees or higher degrees, according to the survey results, released on Thursday. The global average is 92.7 percent.

The average age of the Shanghai teachers is 38, five years younger than the global average.

Shanghai teachers are given an average 63 days a year for training and professional development, double the global average, while Shanghai principals invest less time in administration and more time in teaching than their foreign counterparts, the survey showed.