"Courses Planned"
What seems to be lost in some of these calculations is not so much the command fail rate (an area in which we are clearly an industry leading airline), but the necessity to double count courses when an unsuccessful trainee has his/her 2nd course 18 mths - 2 years later.
The pass rate fluctuates over time because of many factors, sometimes it's 50%, sometimes it's almost 100%, but let's take the 20% alluded to above, and assume not all of those people want, or are given, a 2nd go, so let's say on average over the years, 10% of first time applicants do a second course.
That means a new joiner today isn't waiting for 1600 command courses to transpire before he gets his, it actually means he is waiting for 1760 course.
Some of my numbers are only my best estimates, and any more exact details would be appreciated, but I'm sure you understand the concept.