Why isn't there a shortage of healers?

[Risvertasashi]

The chart is only taking into account classes up to level 30. Since there's only one healer class at that level range (CNJ) and two tank classes (MRD + GLD), that would probably be why there's about double the amount of tanks as there are healers.

I made a mistake in grabbing the URL for the 1 to 30 image instead of the 30 to 50 one. The contrast is less stark but it's still there. Although... the key does seem to indicate that only CNJ is being considered still (so do these graphs count SCHs as ACNs and thus DPS..?)