At the end of the first year there will be: 
1000 + 1000 * 0.02 + 50 => 1070 inhabitants

At the end of the 2nd year there will be: 
1070 + 1070 * 0.02 + 50 => 1141 inhabitants (number of inhabitants is an integer)

At the end of the 3rd year there will be:
1141 + 1141 * 0.02 + 50 => 1213

Tests are not wrong. It is always like that that statistics about people are given. The example of the description clearly show that.
As @Chrono79 said you can consider that they are in the increase per year.

Maybe those are part of the 2% increase per year (of the next year)?