Reuters question: Is the "DEC Monitor Average" a different measurment from the other air quality monitoring locations?

[allyjlevine]

Hi, I'm a graphics reporter with Reuters news agency and looking to make a chart of air quality in New York City today. I've downloaded data from the EHDP website but came to the repo for questions about the "DEC Monitor Average" since it's significantly lower than the other monitoring locations. Is this a different type of measurement from locations like "Midtown-DOT" for example? I'm trying to decide which measurements to include in our chart.

Thanks so much for your time. You can email me back at ally.levine@thomsonreuters.com