However, the most popular names are not as popular as they used to be. That is, the most popular names account for a smaller percentage of births. Emily accounted for 1.2% of girls in 2005; Jessica (the top name for 1995) was 1.5% in 1995; and Jessica (again #1) was 2.6% in 1985. Jennifer, #1 in 1975, was the name of 3.7% of girls born that year. In the early years of the 20th century, more than 5% of girls were named Mary (and 6% of boys were named John). So over time the numbers have gone downward as more parents choose less common names for their kids. The trend holds true if you add up the percentages for the top ten as well.
You can play around with the data yourself on the SSA website:
As usual, I'm interested in the psychological/sociological underpinings that explain this trend. People are now not as willing to give their children common names. Instead, they want their child to have a unique name. It used to be a good thing to have a common, popular name, in order to fit in. Having a weird name would get you made fun of, or beat up on the playground. Now it's considered better to stand out as an individual and be "unique." Parents will say, "I've never heard of anyone named XXXX," and proceed to name their child that. Previous generations were much less willing to make up names, and this SSA data show that the trend reaches beyond Hollywood celebs.
It's yet another indication that American culture has moved steadily toward individualism and uniqueness.