The Population was constantly shifting, as this typically the reason for most states changing their capitals. in Georgia's case they placed a vote in 1847 to decide wether or not to move the Capital To Atlanta for the final time, as it was beginning to vastly outpopulate the capital they had chosen at the time
Yes, this is true.
This is especially evident in countries such as India and Pakistan, which have a very big population and a significant hunger problem- meaning that there is not enough food to feed the whole population.
In a Zero population growth, the number of people stays stable over time.
Independence, marriage, parenting, launching, aging.