array(3) {
  [1]=>
  array(1) {
    [0]=>
    int(2772)
  }
  [9]=>
  array(4) {
    [0]=>
    int(2919)
    [1]=>
    int(2974)
    [2]=>
    int(6601)
    [3]=>
    int(7836)
  }
  [21]=>
  array(1) {
    [0]=>
    int(9630)
  }
}