St. Clair's pre-school creates a budget based on 6 classrooms with an average class size of 15 students each. There are no per student variable costs as most costs are spread across all students in a classroom (for example, the teacher). The Head Teacher set the tuition at $740 per month for 8 months. For the first semester (Sep, Oct, Nov, Dec), the school had 12 students per class, but they added 11 new students to the school (overall, not per class) in for the second semester thanks to a special promotional plan. St. Clair's had budgeted $2,000 for marketing, all of which historically was spent prior to the start of the school year, and this year they actually spent $2,200 in June. In November, however, when they decided to run the special promotion of 1 free month of tuition for January enrollment for the 2nd 4 month semester (Jan, Feb, Mar, Apr). In addition, they spent another $1,500 for advertising this promotion.

CALCULATED VARIABLES: amonths = 620 pmonths = 720

What was St. Clair's volume variance in months of student tuition?