duration generated sqlos.wait_info is in milliseconds

I traced a session (running a single statement) that took over 40 minutes with below event turned on. I collected over 400K events and most of them had the duration 0 and the rest of them summed by duration only added to 110K (110 seconds).

Is this caused by this value is usually less than a millisecond and rounding to 0 or something else is off?

Thank you

CREATE EVENT SESSION [SessionWaits_62] ON SERVER
ADD EVENT sqlos.wait_info(
    WHERE ([sqlserver].[session_id]=(62)))
ADD TARGET package0.event_file(SET filename=N'D:\Data\Data1\Microsoft SQL Server\MSSQL10.UAT1\MSSQL\Log\SessionWaits_62.xel')
WITH (MAX_MEMORY=4096 KB,EVENT_RETENTION_MODE=ALLOW_MULTIPLE_EVENT_LOSS,MAX_DISPATCH_LATENCY=30 SECONDS,MAX_EVENT_SIZE=0 KB,MEMORY_PARTITION_MODE=NONE,TRACK_CAUSALITY=ON,STARTUP_STATE=OFF)

Gokhan Varol