When operating routes, obviously the demand fluctuates with a general peak in the summer months. How often does the demand change though. Is it daily, weekly, monthly (if so, which date of the month) or is it all just completely random. I want to upgrade some of my routes to newer planes but because of the demand fluctuating, I end up opening every single route each time I log in to see if I can upgrade the route yet without losing passengers (as if weekly demand is 100 and I put a 112 plane on it, that fills up but then the demand reduces to 80 for example and if I were to replace the plane with a newer one of the same capacity, I would lose a good 10-15 passengers which is not helpful.
Thanks in advance