diff --git a/flaskr/templates/estimation.html b/flaskr/templates/estimation.html
index 1332bd5..119bff8 100644
--- a/flaskr/templates/estimation.html
+++ b/flaskr/templates/estimation.html
@@ -147,7 +147,7 @@ Math.log10 = Math.log10 || function(x) {
 };
 
 /**
- *
+ * Useful for axes' domains on plots.
  * @param value
  * @returns {number}
  */
@@ -178,6 +178,9 @@ var ceil_value_to_magnitude = function(value) {
 jQuery(document).ready(function($){
 
     var vizid = "#cities_footprints_d3viz";
+    var csvUrl = "/estimation/{{ estimation.public_id }}.csv";
+    var x_key = 'city';
+    var y_key = 'co2 (g)';
 
     // Set the dimensions and margins of the graph
     var margin = {top: 10, right: 30, bottom: 100, left: 100},
@@ -195,7 +198,7 @@ jQuery(document).ready(function($){
               "translate(" + margin.left + "," + margin.top + ")");
 
     // Parse the Data
-    d3.csv("/estimation/{{ estimation.public_id }}.csv", function(data) {
+    d3.csv(csvUrl, function(data) {
 
         // Extrema
         var data_y_max = d3.max(data, function(d) { return parseFloat(d['co2 (g)']); });
@@ -204,7 +207,7 @@ jQuery(document).ready(function($){
         // X axis
         var x = d3.scaleBand()
           .range([ 0, width ])
-          .domain(data.map(function(d) { return d.city; }))
+          .domain(data.map(function(d) { return d[x_key]; }))
           .padding(0.2);
         svg.append("g")
           .attr("transform", "translate(0," + height + ")")
@@ -225,10 +228,10 @@ jQuery(document).ready(function($){
           .data(data)
           .enter()
           .append("rect")
-            .attr("x", function(d) { return x(d['city']); })
+            .attr("x", function(d) { return x(d[x_key]); })
             .attr("width", x.bandwidth())
             .attr("fill", "#d0808b")
-            // Hide bar at the beginning
+            // Hide bars at the beginning
             .attr("height", function(d) { return height - y(0); }) // always equal to 0
             .attr("y", function(d) { return y(0); });
 
@@ -236,8 +239,8 @@ jQuery(document).ready(function($){
         svg.selectAll("rect")
           .transition()
           .duration(800)
-          .attr("y", function(d) { return y(d['co2 (g)']); })
-          .attr("height", function(d) { return height - y(d['co2 (g)']); })
+          .attr("y", function(d) { return y(d[y_key]); })
+          .attr("height", function(d) { return height - y(d[y_key]); })
           .delay(function(d, i) { return(i*100); });
 
         // …
--
libgit2 0.21.2