The subliminal message is just as bad as the obvious one...
Note how the groups mostly overlap. The 'newer' group is shown coming on the scene not that much behind 1914. The distance between the end of the first group, and the second group crossing the line is not that far apart.
Considering that the 1914 generation was basically rendered gone by the first of the century, then the scale of this graph gives the subliminal message that the end is very close.