private int[] getSemesterDistributionData() {
		CourseList model = super.getModel();
		semesterDistribution.clear();
		CourseOffering[] offerings = model.getSelectedCoursesOfferings();
		int semester = 0;
		for(int i = 0; i < offerings.length; i++) {
			semester = offerings[i].getMonthAsColumnIndex();
			if(semester == 1) {
				semesterDistribution.add(0);
			} else if(semester == 2) {
				semesterDistribution.add(1);
			} else if(semester == 3) {
				semesterDistribution.add(2);
			} else { } // do nothing
		}
		return convertData(semesterDistribution);
	}