We have a gas stove, gas furnace, gas water heater, and gas dryer in our questionably insulated south philly row house and going back to 2018 we use about 8 CCF each month during the summer (last month was 9 CCF) is and a high of around 60-70 CCF during the coldest months of the year (granted we're accustomed to keeping our heat turned lower and havent turned it on yet for the winter and have our water heater set to the recommended "safe" temperature so our showers tend to be a bit tepid)

If it were me, I'd definitely be looking into this. But without knowing more about your apartment its hard to say what could be going on. I'd ask your neighbors to compare their monthly usage to see if its just normal for your building.