According to rankings released by the U.S. Social Security Administration, the unique names were the most popular for boys and girls, respectively, in Indiana last year.

Slideshow: 2011's Most Popular Baby Names

Liam, Elijah, Noah and William rounded out the top five boys' list, while Olivia, Ava, Sophia and Isabella were among the most popular for girls.

Nationally, Jacob was the most chosen name for boys for the 13th year.

Mason, which topped Indiana's list, cracked the top 10 nationally for the first time, thought to be spurred on, in part, by reality show celebrity Kourtney Kardashian, who gave her son the name in 2009.

Among girls nationally, Sophia rose from No. 2 in 2010 to claim the No. 1 spot from Isabella, pushing her down to No. 2 in 2011, according to the annual top 10 list.

Over the past 100 years, the names Michael and Mary have held the top spot most often: 44 times in both cases.

The data comes from Social Security card applications for births in the United States.