measurement option can be:
- min: The lowest observed value.
- max: The highest observed value.
- sum: The sum of all observed values.
- variance: The variance of all observed values.
- mean: The average of all observed values.
- stddev: The stddev of all observed values.
- count: The number of observed values.
- median: 50% of all values in the resevoir are at or below this value.
- p75: See median, 75% percentile.
- p95: See median, 95% percentile.
- p99: See median, 99% percentile.
- p999: See median, 99.9% percentile.