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 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.