{
  "color": ["#1991c8"],
  "showInstanceCount": false,
  "pointMarkers": true,
  "precision": null,
  "hideRelativeValue": false,
  "yLabel": "",
  "xml": "<?xml version=\"1.0\" encoding...",
  "excludedColumns": [],
  "columnOrder": {
    "inputVariables": [],
    "instanceProps": [],
    "outputVariables: [],
    "variables": []
  },
  "targetValue": {
    "active": false,
    "values": // see below
  },
  "hideAbsoluteValue": false,
  "xLabel": ""
}

targetValue.values:

Variant 1:
 {
    baseline: "0"
    target: "100"
 }

Variant 2:
 {
  baseline: {value: "01", unit: "hours"}
  target: {value: "22", unit: "days"}
 }

Variant 3:
{
  target: "12", 
  dateFormat: "days", 
  isBelow: false
}

Variant 4:

{
  approveInvoice: {value: 12, unit: "hours"}, 
  reviewInvoice: {value: 1, unit: "hours"},
  ...
}