78: percentage of Americans who report being “extremely” or “somewhat” concerned about not having enough money for retirement, according to a study by Northwestern Mutual . . . $5,000: the median amount of retirement savings for U.S. families, according to the Economic Policy Institute . . . 10: number of new clinicians being added to the Department of Public Health’s Street Medicine Team, which deals with opioid addictions . . . $750,000: per-unit cost of developing affordable housing in San Francisco . . . 100 percent: San Francisco is the only city out of the 97 largest U.S. cities in which 100 percent of its residents live within a 10-minute walk of a public park.