Before the mid 1970's this was common with most small departments, a yearly or bi-yearly qualification, many departments had no qualification AT ALL. During the late 70' early 80' a number of very expensive wrongful death law suites on a national level effected the mind sets of risk assessment folks and training was re-thought.
I do not know where you live, however, many of the western state have mandated very progressive training programs. The problem is the mid set of many in the leadership roles within departments believe that "training to a minimum legal standard" is good enough. Budgets, local politics, departmental infighting and much much more can affect how frequently training occurs.
Many officers (including myself) spent their own $$$$ to attend additional training. To latter pass it on to their peers.
Sounds to me like the folks in power at your location, have not been bitten by the law suite bug. Unfortunately sometimes there has to be LEO blood on the street before BEAN COUNTERS get it!
Good Luck & Be Safe
First, with the most, WINS!
Regards, Scattergun Bob