The graph shows the number of students in the age range 19 to 24. As an overall trend, it is clear that the number of students increased rather continuing until peak at about 150 and before dropping until the age of 24.
Age 19, the number of ages students at approximately 18. That number rose slightly to 22 by ages 20 and increase dramatically about 139 in ages 21. That number hit a peak to 150 in ages 22. At this point the number of age students drop gradually to 70 in ages 23 before slumped to 10 in ages 24.
To sum up, the graph shows the number of students increase and decrease in the age range 19 to 24.