agea numeric vector (years).
heighta numeric vector (cm).
menarchea numeric vector. Has menarche occurred (code 1: no, 2: yes)?
sexa numeric vector (1: boy, 2: girl).
igf1a numeric vector, insulin-like growth factor
(\(\mu\mathrm{g}/\mathrm{l}\)).
tannera numeric vector, codes 1--5: Stages of puberty ad modum Tanner.
testvola numeric vector, testicular volume (ml).
weighta numeric vector, weight (kg).