Analysis of Scheduling.Browser.DrawInterval2 suggests unexpected variation in value at 50th percentile of Scheduling.Browser.DrawInterval2 on Android and Mac.
+----------+---------+-----------------+-------+------+-------------+--------------------------+-------------------------------------------+------------+--------------+----------+--------+
| Platform | Channel |    Statistic    |  Type | Link | probability | value at 50th percentile | recent median of value at 50th percentile | MAD (past) |     unit     | ~samples | ~users |
+----------+---------+-----------------+-------+------+-------------+--------------------------+-------------------------------------------+------------+--------------+----------+--------+
| Android  | DEV     | 50th percentile | spike | [1]  |  1.0973e-04 |                 16856.33 |                                  16850.57 |       1.06 | microseconds |    217 M |   96 k |
| Mac      | DEV     | 50th percentile | spike | [2]  |  8.0014e-08 |                 17025.08 |                                  16737.27 |      17.69 | microseconds |    488 k |    5 k |
+----------+---------+-----------------+-------+------+-------------+--------------------------+-------------------------------------------+------------+--------------+----------+--------+
Note: data has been smoothed over 5 days using median function.

Links:
[1]: https://uma.googleplex.com/timeline_v2?q=%7B%22day_count%22%3A%2249%22%2C%22end_date%22%3A%222018%2F05%2F12%22%2C%22entries%22%3A%5B%7B%22bucket%22%3A%22%22%2C%22logScale%22%3Afalse%2C%22measure%22%3A%22percentile%22%2C%22percentile%22%3A%2250.0%22%2C%22showLowVolumeData%22%3Atrue%2C%22zeroBased%22%3Afalse%7D%5D%2C%22filters%22%3A%5B%7B%22fieldId%22%3A%22platform%22%2C%22operator%22%3A%22EQ%22%2C%22selected%22%3A%5B%22A%22%5D%7D%2C%7B%22fieldId%22%3A%22channel%22%2C%22operator%22%3A%22EQ%22%2C%22selected%22%3A%5B%222%22%5D%7D%2C%7B%22fieldId%22%3A%22milestone%22%2C%22operator%22%3A%22GE%22%2C%22selected%22%3A%5B%2266%22%5D%7D%5D%2C%22histograms%22%3A%5B%22Scheduling.Browser.DrawInterval2%22%5D%2C%22window_size%22%3A5%7D&source=chirp%3ATimeline
[2]: https://uma.googleplex.com/timeline_v2?q=%7B%22day_count%22%3A%2249%22%2C%22end_date%22%3A%222018%2F05%2F12%22%2C%22entries%22%3A%5B%7B%22bucket%22%3A%22%22%2C%22logScale%22%3Afalse%2C%22measure%22%3A%22percentile%22%2C%22percentile%22%3A%2250.0%22%2C%22showLowVolumeData%22%3Atrue%2C%22zeroBased%22%3Afalse%7D%5D%2C%22filters%22%3A%5B%7B%22fieldId%22%3A%22platform%22%2C%22operator%22%3A%22EQ%22%2C%22selected%22%3A%5B%22M%22%5D%7D%2C%7B%22fieldId%22%3A%22channel%22%2C%22operator%22%3A%22EQ%22%2C%22selected%22%3A%5B%222%22%5D%7D%2C%7B%22fieldId%22%3A%22milestone%22%2C%22operator%22%3A%22GE%22%2C%22selected%22%3A%5B%2266%22%5D%7D%5D%2C%22histograms%22%3A%5B%22Scheduling.Browser.DrawInterval2%22%5D%2C%22window_size%22%3A5%7D&source=chirp%3ATimeline

Terminology explained...
	probability: The probability of observing variation as big or greater due to chance.
	MAD: [Median of absolute deviations (from median)](http://en.wikipedia.org/wiki/Median_absolute_deviation)
	Warning! The Chirp will not resend messages for a week unless something changes.
	~samples: An approximate number of daily observation (the median of single day of counts in all bins of the histogram over the last 7 days).
	~users: An approximate number of unique users per day (the median over the last 7 days).