某国18至34岁人口占比以及该年龄段人群在不同地区居住的比例

The graph and pie charts below show the percentage of population aged between 18 and 34 years old in a particular country and the percentage of this age group of people living in different regions from 1978 to 2011. Summarize the information by selecting and reporting the main features and make comparisons where relevant.