Immunizations for Adolescents – The percentage of adolescents 13 years of age who had one dose of meningococcal vaccine and one tetanus, diphtheria toxoids and acellular pertussis vaccine (Tdap) or one tetanus, diphtheria toxoids vaccine (Td) by their 13th birthday.
Further reading –
http://www.ncqa.org/portals/0/Immunizations%20for%20Adolescents.pdf