PY: The long term solution is in girls starting to date SLIGHTLY later and boys SLIGHTLY earlier. There is no need for them to be exact same age. Long term AVERAGE gap of one year is fine. For the short term w/o having implemented any MINOR structural changes yet the effective course of ages has been to have more close in age marriages which essentially accomplishes the same end.
Please note that not a single push has been made to the girls and their parents to push off dating – because they WON’T listen at this juncture. However if more boys marry girls 21-25 obviously fewer girls 19/20 will be getting married.