The three given pie charts compare the proportions of students who chose various course types over three periods: 1984, 1994, and 2004.
Overall, the most popular type of course was face-to-face subject, accounting for the largest share, while online courses were the smallest category throughout the period.
According to the charts, we can clearly see that the most popular type of course was face-to-face courses between 1984 and 2004, even in 2004 the percentage was 5 percentage points higher than that of mixed-made courses. In contrast, online courses were the least popular compared with others; they appeared in 1994 and accounted for 11%, and 10 years later decreased minimally to just 1%. It is explicitly observed that the rest of the classes, such as correspondence courses and mixed-made courses, made up one third in 1984, remained stable in 1994, and almost a half if online programmes are included, and over half, just over 65%, in 2004.
