"Calculation is simple - 15 elements in 6 months make for a 2.5 element per month".
Very simple, though you need to count March, April, May, June and July as 6 months.
April Fool's Day. April My Day.
Oh well, 15 elements in 5 months, so I need to finish 3 elements each month. Anyone cares to do a check run for me, just in case?