code: function genPercentAdd() {
    var k = 0.1;
    var i = 0.01;
    var end = 0.98;
    return function (s) {
      var start = s;
      if (start >= end) {
        return start;
      }
  
      start += k;
      k = k - i;
      if (k < 0.001) {
        k = 0.001;
      }
      return start * 100;
    };
  }
docs: 生成Progress percent: 0.1 -> 0.98
  - for ie