Course capacity per level

[EmCousin]

What we currently have is a global capacity per course. Say, the Monday Course can welcome 60 members, regardless of members' levels.

The problem is that it can lead to a course having 99% entry-level members and 1% advanced-level members, which is not something that we want. What we want for each course is to have as diverse members as possible, which equal proportions of members for each level.