The most unisex names in US history | FlowingData
http://flowingdata.com/2013/09/25/the-most-unisex-names-in-us-history/
1930年から2012年までの様子をグラフに。推移が突然変化するのは何かがあった証拠。例えばArielはディズニーの人魚姫が公開されると女の子の名前として定着した。
Moving on from the most trendy names in US history, let’s look at the most unisex ones. Some names have always been predominantly male, such as Frank and Joseph, and some names are mostly female, such as Jessica and Michelle. However, there is a small group of names that is split between male and female. The charts above show the most unisex names between 1930 and 2012.