Population by birth gender over time - based on example from https://vega.github.io/vega-lite/docs/stack.html#normalized

population-gender.vl.json

{
  "$schema": "https://vega.github.io/schema/vega-lite/v2.json",
  "vconcat": [
    {
      "width": 600,
      "height": 300,
      "mark": "bar",
      "data": {
        "url": "data/population.json",
        "format": {
          "type": "json"
        }
      },
      "transform": [
        {
          "filter": "datum.year == 2000"
        },
        {
          "calculate": "datum.sex == 2 ? 'Female' : 'Male'",
          "as": "gender"
        }
      ],
      "encoding": {
        "y": {
          "aggregate": "sum",
          "field": "people",
          "type": "quantitative",
          "axis": {
            "title": "population"
          }
        },
        "x": {
          "field": "age",
          "type": "ordinal",
          "scale": {
            "rangeStep": 17
          }
        },
        "color": {
          "field": "gender",
          "type": "nominal",
          "scale": {
            "range": [
              "#EA98D2",
              "#659CCA"
            ]
          }
        }
      }
    },
    {
      "width": 600,
      "height": 300,
      "mark": "bar",
      "data": {
        "url": "data/population.json",
        "format": {
          "type": "json"
        }
      },
      "transform": [
        {
          "filter": "datum.year == 2000"
        },
        {
          "calculate": "datum.sex == 2 ? 'Female' : 'Male'",
          "as": "gender"
        }
      ],
      "encoding": {
        "y": {
          "aggregate": "sum",
          "field": "people",
          "type": "quantitative",
          "axis": {
            "title": "population"
          },
          "stack": "normalize"
        },
        "x": {
          "field": "age",
          "type": "ordinal",
          "scale": {
            "rangeStep": 17
          }
        },
        "color": {
          "field": "gender",
          "type": "nominal",
          "scale": {
            "range": [
              "#EA98D2",
              "#659CCA"
            ]
          }
        }
      }
    }
  ]
}