The studies were published in a lapse of 34 years, between 1978 and 2012: 23% between 1978 and 1999; 58% between 2000 and 2009; 19% between 2010 and 2012.
Los estudios fueron publicados en el lapso de 34 años entre 1978 y 2012: 23% entre 1978 y 1999; 58% entre 2000 y 2009; 19% entre 2010 y 2012.