1,070 feet: height of the Salesforce Tower, which will be the city’s tallest building when it is completed in 2018 … 5,500: number of backpacks distributed to San Francisco schoolchildren as part of Mayor Ed Lee’s Backpack Giveaway program … 3 and counting: the number of attempts to get a “Calexit” referendum on the state ballot to have voters decide whether to try to leave the union … 20 jumbo jets: the passenger load equivalent of the number of people killed in the United States each year in drunk-driving accidents, according to the SFPD in announcing its deployment of anti-DUI forces for Labor Day weekend … $19.2 million: amount San Francisco will spend over two years to provide home-delivered meals to seniors, people with disabilities, and families in the city … 350,000: number of California Republicans who are considering abandoning the party over its position on climate change, according to the party’s own poll.