Average Availability difference in SWQL Query and Web Report Writer

Hi

I am always getting different result as compare to SWQL Query and Web Report Writer.

Mentioned is Report of Average Availability LAST MONTH.

SWQL Result:

SELECT
concat(round(avg(Availability), 2), ' %' ) as supernet
FROM Orion.ResponseTime rt
where
monthdiff(datetime,getdate())=1 and rt.Node.CustomProperties.SLA_LTE ='supernet'

Web Report Result:

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