Source OP’s comment:
Source: birth rates in the US, from social security card applications. Provided by SSA.gov. For the age ranges, we make the assumption that all women lived to exactly 73 years old, which is the life expectancy for females at birth in 1960. Therefore, the population in each age range will not be entirely accurate, particularly for 69+, but it nonetheless shows the trends of birth rates and popularity of these names over time. Tools: python, pandas, Vega>
Now the question is whether Lou Bega looked at English names to use in the song or German ones :D
But they do sound like he might have used popular German names at the time and simply converted them to the English versions imo