array(6) {
  [0]=>
  string(4) "2017"
  [1]=>
  string(4) "2018"
  [2]=>
  string(4) "2021"
  [3]=>
  string(4) "2022"
  [4]=>
  string(4) "2023"
  [5]=>
  string(4) "2026"
}