In addition to the natural movement of numbers, there is a mechanical movement, which is characterized by migratory changes. If the number of immigrants exceeds the number of emigrants, the migration rate has a positive value. These migration processes are studied in detail by the International Organization for Migration (IOM) in Ukraine [11, 12].

Let’s build a graph of migration growth of the population of Ukraine (Fig. 1.3).

The graph illustrates the wave-like migration movement.

From 1990 to 1993, migration growth was positive. Immigrants came to Ukraine in greater numbers than emigrants left. On average, the number of immigrants annually exceeded the number of emigrants 142.98 thousand people.

From 1994 to 2004, migration growth was negative. The number of emigrants was more than the number of immigrants per year by an average of 111.04 thousand people.

From 2005 to 2020, there was a slight excess of the number of immigrants over the number of emigrants (positive migration growth). On average, this difference amounted to 18.67 thousand people annually.

As a result of the unification of natural and mechanical population movements, population dynamics was formed.