Mexico posted its highest homicide rate in decades, with the government reporting Sunday there were 29,168 murders in 2017, a 27 percent increase over 2016. The number is the highest since comparable records began being kept in 1997 and is also higher than the peak year of Mexico’s drug war in 2011, when there were 27,213 killings. The Interior Department, which posted the number, reported the country’s homicide rate was 20.5 per 100,000 inhabita…