That was over a 24-year period.
Don’t know about the Navy but the Army’s previous drawdowns occurred in only a few years. After Vietnam, the Army drew down from 1.3 million to 780,000 in 4 years. The drawdowns in the early 90s reduced the Army from 770,000 to 490,000 in a little over 5 years. This was despite a hold on force reductions put in place for the 91 Gulf War.
Democratic Presidents love to slash military forces.