Attempted sarcasm aside, this is an interesting statistical question. The total birthrate includes all the children born, regardless of the ethnic or economic characteristics of the mother. If "Bad People Group X" are having a lot of children, that means the birthrate of "Good People Group Y" is even lower than the general rate suggests.
However, for those concerned about the racial makeup of the replacement population, this chart shows that the difference in total fertility rate among ethnic classes is very modest.