Yes, residents living in an earthquake-prone area should be concerned about a future earthquake, even if the last earthquake had been many years before. Remember, an earthquake-prone area is an area that has frequent earthquakes (earthquakes that happen all the time). So, even if an earthquake hasn't happened in a few years, it doesn't mean that it won't happen again. If you live in an earthquake-prone area, make sure to always have emergency supplies with you at all times, and in case of a major earthquake, stay with an adult, and make sure that you have water and food.
~Hope I helped!~