I'm on a standard map, about 700 turns gone and I acquired Napoleon's empire of around 7 cities, over 200 turns ago. For some time i've struggled with happiness/economy staying in the green. I have my happiness under control but I just can't get my economy under control. So I did some more investigating and realized that I had 16 workers. Upon disbanding one worker my GPT increased by 10. So I checked the Economic Overview and it states that the cost for maintaining each unit is 9.08 gold. Which increases with the total number and over time. The part i'm confused about is the "over time" part. Does it mean that if I keep these same 16 works for another turn they will each be slightly more expensive? This doesn't make sense to me, why would the age of a unit determine how much it costs? If I disband one of these workers and create a new one, is it cheaper? Just slightly confused here.