I like in a similar aged condo building - in my 10 years their we had one special assessment of $4500 payable over 36 months to top up our reserve fund.  Otherwise we do has annual increases most going to our reserve but we have a substantial fund even after redoing the roof, HVAC and boilers.  We are currently doing cosmetic upgrades and evaluating new window options.  

You need a good board and I think it helps that only about 10% of our condos are rentals.