[рони]

Perepelenok,

$(function() {
        var tabs = $(".tab_content");
        tabs.each(function(i, parent) {
            var obj = {};
            $("[data-year]", parent).each(function() {
                var el = $(this),
                    year = $(this).data("year"),
                    p = obj[year];
                if (p) el.appendTo(p);
                else obj[year] = el.wrap("<p/>").parent()
            })
            Object.keys(obj).sort(function(a, b) {
                return b - a
            }).forEach(function(year) {
                obj[year].appendTo(parent)
            })
        })

    });