<prompt> Translate the following text to SwahiliThey then fit VSL as a function of age and extrapolate outside the range of the data to obtain ratios for the very old.  <response>: Kwa hivyo, kwa kutumia VSL, watu wengi wanafanya kazi ya umri na kupanua nje ya kiwango cha data ili kupata uwiano wa umri wa miaka. 