The number of American households headed by single fathers has ballooned over the last five decades, according to a new study by the Pew Research Center.

Single-father-led households in the U.S. have risen about nine-fold from less than 300,000 in 1960 to over 2.6 million in 2011, Pew says. A record 8% of households with minor children in the U.S. are headed by a single father, up from just over 1% in 1960, according to Pew, which analyzed Census data. Single-mother households have increased four-fold in the same time period.