How many insects have died in them over that period?
And on a much more serious note, are you noticing a year-on-year decline in numbers?
Since the move to much cooler/colder running LED lamps, I have yet to see any insects frazzled by the heat from a lamp. In addition to which, the only door we have open during the daylight hours, is fitted with a insect screen, we rarely get flying insects, indoors anyway.

