[{"sf": "DOD", "lfs": [{"lf": "Department of Defense", "freq": 159, "since": 1977, "vars": [{"lf": "Department of Defense", "freq": 156, "since": 1981}, {"lf": "department of defense", "freq": 1, "since": 2000}, {"lf": "Departments of Defense", "freq": 1, "since": 2000}, {"lf": "Department  of Defense", "freq": 1, "since": 1977}]}, {"lf": "dead of disease", "freq": 20, "since": 1988, "vars": [{"lf": "died of disease", "freq": 10, "since": 1989}, {"lf": "dead of disease", "freq": 10, "since": 1988}]}]}]