docs: public void update(double sample) {
          // Adjust min&max
          min = (sample < min ? sample : min);
          max = (sample > max ? sample : max);
  
          // Update average
          average += (sample - average) / ++count;
          _pwrSumAverage += ( sample * sample - _pwrSumAverage) / count;
  
          // Update variance
          stdDev = Math.sqrt((_pwrSumAverage * count - count * average * average) / (count - 1));
          cv = 100 * (stdDev / average);
      }