/**
 * year start count from
 * input @string ('1987')
 * return years since @string
 */
function year_skils($Y) {
  $years = date("Y") - date("Y", strtotime($Y));
  $year_text = ($years%2==0|$years%3==0|$years%4==0)?"года":(($years%10==1&&$years!=11)?"год":"лет");
  return $years . " " . $year_text;
}