Here is the game news from February when some changes were made to pop.
29. Population [ top ]
Population growth is faster for countries with lower numbers of population. We have now lifted the limits, and growth will be faster and continue into higher population numbers.
At population levels of 70 or 80 millions, growth will depend more on the health index in the country and numbers can keep growing.
All this is true for premium accounts and growth can be accelerated by the purchase of additional population on the direct trading market.
For free accounts, population numbers will increase fast up to a population level of about 20.000.000. Growth will then stop and these countries will stay at around that number.
Free account countries with a population larger than 20.000.000, will see further declines and the number will settle at around 20.000.000.