years – Use figures, even when starting a sentence with a year. Express inclusive years either as 1955 to 1975 or 1955-75 (use the slash, or virgule, in place of the hyphen only to express fiscal years). Never write from 1955-1975; it is from 1955 to 1975. Use an s without an apostrophe to indicate spans of decades or centuries. Examples: 1800s, gay 90s.