#occurrence {
  dot-width: 2;
                 [total <=    10] { dot-fill: #FFFF00;  }
  [total >    10][total <=   100] { dot-fill: #FFCC00;  }
  [total >   100][total <=  1000] { dot-fill: #FF9900;  }
  [total >  1000][total <= 10000] { dot-fill: #FF6600;  }
  [total > 10000]                 { dot-fill: #D60A00;  }
}
