How Big is Istanbul

One of the real questions regarding our service in Turkey is the actual size of our new city, Istanbul.  We have heard and seen a variety of population reports that say the population is anywhere from 13 million to as much as 25 million.  The official (?) census report indicates 18 million.
What ever the real number, this will be true big city living.
Interestingly enough we are excited to try living within a metropolis and discovering one of the worlds oldest cities.  Of course it is no longer Constantinople, but it is rich in history and full of historical wonders.  Modern yet supposedly still dependent on historical practices.
We plan to count all the people when we get there so we know how many really reside in Istanbul.
Currently the city is being impacted by an influx of refugees from Syria, Iran and Lebenon.  The current humanitarian couple are working with these refugees to find homes and means of support.  The majority of these people are young men trying to escape forced conscription into the army.
This is a typical picture of Anita Canfield (the folks we will replace) and some local people.  Anita is on the left.