For "new" schools like CSS and VSA, students' performance varies, whereas the average score for CDNIS is higher (this would be the 2nd cohort after CDNIS adopts IBDP). CIS' average score for 2011 was 37. So, still lots of room for improvement for CSS and VSA students.
To make it clear, this is VSA's 2nd cohort of students who studied all the way from kindergarten. Our first and second cohorts of IBDP students joined VSA for IBDP only.