above(threshold, fixed, unconverted) {
    const recorded_values = this.get_recorded_values(unconverted);
    let result = 0;

    if (recorded_values.length > 0) {
      if (threshold == null) { threshold = this._above_threshold; }
      if (threshold != null) {
        for (let i = 0, il = recorded_values.length; i < il; i++) {
          if (recorded_values[i] > threshold) {
            result++;
          }
        }
        result = this._to_fixed((result / recorded_values.length) * 100.0, fixed);
      }
    }

    return `${result}%`;
  }
Calculates how often the entries were above a threshold as a percent.
@param {Number} [threshold=0]
@param {Number} [fixed=2] number of digits to appear after the decimal point
@param {Boolean} [unconverted=false] whether to get the raw recorded values
@returns {String}