$interval = 500;
%HoAoHoA = (
  'I' => [
     {$a => [4,10,200],
      $b => [75,350],
      $c => [0, 95]},

     {$a => [6000],
      $b =[5900],
      $c =>[5990]},

     {$a => [],
      $b =[6402],
      $c =>[6450]},

     {$a => [7000,7100],
      $b =[7110],
      $c =>[]},