The murder rate in the United States in 2018 is on track for the largest one-year drop in five years.

The numbers obviously aren’t final, and the F.B.I. won’t formally report 2018’s murder figures until September 2019.

But based on a comparison of 2017 data and 2018 data for 66 large American cities (population over 250,000), we can observe the trend as it is occurring and offer a reasonable forecast. (The 2018 data I’ve collected is available here).

Murder rose 23 percent nationally between 2014 and 2016 before leveling off in 2017. Major increases in murder in Chicago and Baltimore received much of the national attention, but the increase occurred throughout the country.