UI will not display statistics is grab_stats_every_n_ticks > 2 in static_config

When adjusting the value for "grab_stats_every_n_ticks" in /opt/couchbase/etc/couchbase/static_config if it is set to 3 or greater the UI no longer displays statistics.  If the parameter is not present or set to 1 or 2 it works.

{grab_stats_every_n_ticks, 1}

.

{grab_stats_every_n_ticks, 2}

.

fails to show any stats in the UI 

{grab_stats_every_n_ticks, 3}

.

{grab_stats_every_n_ticks, 10}

.