ChartDataPostProcessingOperation

{
    "operation": "aggregate",
    "options": {
        "aggregates": {
            "age_mean": {
                "column": "age",
                "operator": "mean"
            },
            "age_q1": {
                "column": "age",
                "operator": "percentile",
                "options": {
                    "q": 0.25
                }
            }
        },
        "groupby": [
            "country",
            "gender"
        ]
    }
}