I've called more than a dozen times over the years. First time I was a teenager, when our house was on fire (no injuries to family, firefighters, or pets, thankfully, though we lost a couple of family heirlooms, and we had to live in my grandparents' house for four months).
I called several times when I was in college, including reporting that some guys were using a water-balloon slingshot to bombard passing cars from the balcony of a fraternity, that an intoxicated person had fallen off a wall behind my dorm (apparently he wasn't seriously injured), that I'd been involved in a minor traffic accident, that there was a traffic accident with injuries near my dorm, that I was having heart palpitations from an accidental overdose of asthma medication (only time I've ever ridden in an ambulance), and, finally, that the dumpster behind my apartment building was on fire (it was the Fourth of July, and one of my roommates tried to convince me to wait to call because he wanted to shoot off some illegal fireworks, but I called anyway).
Since then I've called at least twice each to report being in a minor traffic accident, report a disabled vehicle, report debris on the highway, and report a malfunctioning traffic signal.
I've also called once each for another accidental overdose (paramedics checked me out but they said I seemed okay, so I didn't go to the hospital; I take safer asthma medications now), to report a car driving erratically, and to report a broken water main.