The first bar chart
s compares students of different ages in terms of why they study and the second chartcompares whether they are supported by an employer different levels of support from employers.
the proportion of students
However is an inappropriate word. You could use "Also" instead.
both younger groups
You should mention the ages of the groups.
by more than 50 per cent
by under 47 per cent than both former groups
this proportion is still higher
students aged 30-to-39
A more details looked at the bar graph reveals that the proportion of study purposes is not always similar.
This sentence could be removed.
for of interest purpose
Therefore, while is seen from the overall groups, student age 40-to-49 shows the similar percentage of study purpose.
This sentence is pretty confusing.