<prompt> Translate the following text to EnglishKwa bahati mbaya, kwa sababu VSL ni quadratic katika umri, extrapolation zaidi ya mbalimbali ya data inaweza kusababisha kupungua kali sana katika VSL katika umri zaidi ya 75.  <response>: Unfortunately, because VSL is specified as quadratic in age, extrapolation beyond the range of the data can lead to a very severe decline in VSL at ages beyond 75. 