function filterData(apiData) {
  var dataPoints;

  for (var i = 0; i < apiData.length; i = i + 1) {
    if (apiData[i].meta.n1 == "ogółem" && apiData[i].meta.n2 == "ogółem") {
      dataPoints = apiData[i].data.results[0].values;
    }
  }

  return dataPoints;
}


fetch("https://cors-anywhere.herokuapp.com/http://satyrium.pl:8080/work/media-3.0-datavis-course/data.json")
  .then(function(data) {
    return data.json()
  })
  .then(function(result) {
    var filtered = filterData(result);
  
    document.body.innerHTML = "<pre>" + JSON.stringify(filtered, null, 2) + "</pre>";
  });