[рони]

Х3 кто,
вариант ... замените весь код на это

$(function() {
    $("#test").change(function() {
        var pok = this.value;
        var namepok = this.options[this.selectedIndex].text;
        var temp_array = regions.map(function(item) {
            return item[pok]
        });
        var highest_value = Math.max.apply(Math, temp_array);
        regions.forEach(function(el) {
            var title = el.region_name + "<br>" + namepok + " " + el[pok];
            $("#" + el.region_code).css({
                "fill": "rgba(0,255,100," + el[pok] / highest_value + ")"
            }).data("title", title)
        })
    }).change();
    var info_panel = $('<div class="info_panel">').appendTo("body").hide();
    $(".map").on("mouseenter", "g",
        function(e) {
            var title = $(this).data("title");
            info_panel.html(title).show()
        })
    .mouseleave(function() {
        info_panel.hide()
    })
    .mousemove(function(e) {
        var mouseX = e.pageX,
            mouseY = e.pageY;
        info_panel.css({
            top: mouseY - 50,
            left: mouseX - info_panel.width() / 2
        })
    })
});