jmeter influxdb backend listener and querying

[Tong Sun]

So I added the standard jmeter influxdb backend listener, with default
setting of

percentiles: '90;95;99'

and I can query the influxdb backend DB using:

SELECT mean("pct90.0") FROM "$measurement_name"

The question is, how to query its *mean *values?
I tried the following but failed:

SELECT mean("pct50.0") FROM "$measurement_name"