[
    {
        "num_entries": 5,
        "years": [
            1700,
            1720,
            1740,
            1760,
            1780
        ],
        "attributes": {
            "windmills": [
                "Molen A",
                "Molen B",
                "Molen C",
                "Molen D",
                "Molen E"
            ],
            "families": [
                "Family 1",
                "Family 2",
                "Family 3",
                "Family 4",
                "Family 5"
            ]
        }
    },
    {
        "num_entries": 4,
        "years": [
            1683,
            1706,
            1729,
            1752
        ],
        "attributes": {
            "windmills": [
                "Vlietmolen",
                "Westmolen",
                "Zemelmolen",
                "Other"
            ],
            "families": [
                "Van Dijk",
                "Visser",
                "De Jong",
                "Other Family"
            ]
        }
    },
    {
        "num_entries": 5,
        "years": [
            1800,
            1825,
            1850,
            1875,
            1900
        ],
        "attributes": {
            "windmills": [
                "A",
                "B",
                "C",
                "D",
                "E"
            ],
            "families": [
                "1",
                "2",
                "3",
                "4",
                "5"
            ]
        }
    },
    {
        "num_entries": 3,
        "years": [
            1600,
            1650,
            1700
        ],
        "attributes": {
            "windmills": [
                "Old Molen",
                "Middle Molen",
                "New Molen"
            ],
            "families": [
                "Ancient Family",
                "Middle Family",
                "Modern Family"
            ]
        }
    }
]