The graph below shows the number of students who got prizes in the National exams for excellent students from 2008 to 2011 in three provinces. Summarise the information by selecting and reporting the main features and make relevant comparisons where relevant.

The line graph compares the number of candidates winning prizes in the National Excellent Student Contest across three different provinces namely Yên Tây, Yên Bắc and Yên Nam over a span of four years, commencing from 2008. Overall, there was a similar upward trend in the quantity of students being awarded prizes in Yên Bắc and Yên Tây while Yên Nam witnessed a contrasting movement. From a low of almost 15 in 2008, the number of participants getting prizes in Yen Bac climbed gradually to well over 30 in 2011, making an overall upsurge of more or less 15 students. Such a growth rate was comparatively equivalent to that in the case of Yen Bac, despite a sharp slide of around 22 students from its peak of 52 students in 2010. On the contrary, in 2008, prizes were handed out to roughly 38 contestants in Yen Nam, accounting for the highest number among three surveyed provinces in the same year. The figure, however, underwent a substantial decrease of 8 by 2009, which was followed by a negligible upturn to barely more than 30 in 2010. The number of students winning awards in Yen Nam again went down precipitously and ended its period at almost 20, yielding an overall reduction of 18 students over the same time frame.