capture program drop covamu
program define covamu
  version 8.0
  local i = 1
  while "``i''" ~= "" {
    quietly summarize ``i''
    local v1 = r(sd)/r(mean)  /* coefficient of variation */
    display "Coefficient of variation for ``i'' = " `v1'
    local i = `i' + 1
  }
end