{
  "range_key(1750,1967)":
  {
    "0":"0 knots",
    "1":"1-3 knots",
    "2":"4-6 knots",
    "3":"7-9 knots",
    "4":"10-12 knots",
    "5":"13-15 knots",
    "6":"16-18 knots",
    "7":"19-21 knots",
    "8":"22-24 knots",
    "9":">24 knots"
  },
  "range_key(1968,yyyy)":
  {
    "0":"0 knots",
    "1":"1-5 knots",
    "2":"6-10 knots",
    "3":"11-15 knots",
    "4":"16-20 knots",
    "5":"21-25 knots",
    "6":"26-30 knots",
    "7":"31-35 knots",
    "8":"36-40 knots",
    "9":">40 knots"
  }
}