The vaccine was introduced in 2008 to 5% of the population. This percentage of the population had the lowest development index which correlates with the highest incidence of cervical cancer. The HPV vaccine is delivered to girls 12 – 16 years old following the 0-2-6 dosing schedule. By 2009 Mexico had expanded the vaccine use to girls, 9–12 years of age, the dosing schedule in this group was different, the time elapsed between the first and second dose was six months and the third dose 60 months later. In 2011 Mexico approved a nationwide use of HPV vaccination program to include vaccination of all 9-year-old girls.