Ranged Dot Plot

{
  "$schema": "https://vega.github.io/schema/vega-lite/v2.json",
  "description": "A ranged dot plot that uses 'layer' to convey changing life expectancy for the five most populous countries (between 1955 and 2000).",
  "data": {"url": "data/countries.json"},
  "transform": [
    {
      "filter": {
        "field": "country",
        "oneOf": ["China", "India", "United States", "Indonesia", "Brazil"]
      }
    },
    {
      "filter": {
        "field": "year",
        "oneOf": [1955, 2000]
      }
    }
  ],
  "encoding": {
    "x": {
      "field": "life_expect",
      "type": "quantitative",
      "axis": {
        "title": "Life Expectancy (years)"
      }
    },
    "y": {
      "field": "country",
      "type": "nominal",
      "axis": {
        "title": "Country",
        "offset": 5,
        "ticks": false,
        "minExtent": 70,
        "domain": false
      }
    }
  },
  "layer": [
    {
      "mark": "line",
      "encoding": {
        "detail": {
          "field": "country",
          "type": "nominal"
        },
        "color": {"value": "#db646f"}
      }
    },
    {
      "mark": {
        "type": "point",
        "filled": true
      },
      "encoding": {
        "color": {
          "field": "year",
          "type": "ordinal",
          "scale": {
            "domain": [1955, 2000],
            "range": ["#e6959c", "#911a24"]
          },
          "legend": {
            "title": "Year"
          }
        },
        "size": {"value": 100},
        "opacity": {"value": 1}
      }
    }
  ]
}