Well for that world, the game will start on 1 Jan 1990 and end at any date in 2010, at a rate of 5 minutes (real-life) per game day. This means every 5 minutes in real life, the world progresses a day.
If you started the airline on the start date (1 Jan 1990), and let's say the game ends on the last day of the year 2010 (31 Dec 2010), this brings us a total of approximately 7669 game days, given that it progresses at a rate of 5 real-life mins/game day, your airline will last for 38345 minutes in real-life, or approximately 26 real-life days.
However, the results above depends on the end date, the date when you started your airline, and the exact number of days between the start and end dates.
Cheers