Latin terms for anniversaries [from Wikipedia: Anniversaries]

• Annual - 1 year
• Biennial - 2 years
• Triennial - 3 years
• Quadrennial - 4 years
• Quinquennial - 5 years
• Sexennial - 6 years
• Septennial - 7 years
• Octennial - 8 years
• Novennial - 9 years
• Decennial - 10 years
• Undecennial - 11 years
• Duodecennial - 12 years
• Tredecennial - 13 years
• Quattuordecennial - 14 years
• Quindecennial - 15 years
• Vigintennial or vicennial - 20 years
• Semicentennial or quinquagenary - 50 years
• Semisesquicentennial - 75 years
• Centennial - 100 years
• Quasquicentennial - 125 years
• Sesquicentennial - 150 years
• Demisemiseptcentennial or quartoseptcentennial - 175 years
• Bicentennial - 200 years
• Semiquincentennial - 250 years
• Tercentennial or tricentennial - 300 years
• Semiseptcentennial - 350 years
• Quadricentennial or quatercentenary- 400 years
• Quincentennial - 500 years
• Sexcentennial - 600 years
• Septcentennial or septuacentennial - 700 years
• Octocentennial - 800 years
• Nonacentennial - 900 years
• Millennial - 1000 years
• Bimillennial - 2000 years