In the USA,
Diana increased in use by about 70% just after
Diana married
Prince Charles in 1981. It had begun to decrease again when
Diana's tragic death in 1997 seems to have caused a sudden 30% spike upward in the name. The 1997 increase, however, seems to have been largely confined to the Hispanic-American community. Hispanics are more likely to go in for commemorative naming in response to celebrity deaths than people from other American subcultures are, it seems.