The defense claim: "(The noise is caused by) a tremendous increase of aircraft operations in recent years. We are currently averaging between 1200-1400 aircraft operations a day."
Source: The SFO Noise Abatement Office email, April, 2019
This is from the flysfo.com website published in April, 2019: "While passenger traffic has grown by 36% since 2011, the number of flights at SFO has only grown by 14%..."
Aircraft movements had been steady at an average of 1200 per day for several years.