Oracle Query to Find Leap Year

select 1994, decode( mod(1994, 4), 0,
                     decode( mod(1994, 400), 0, 'Leap Year',
                     decode( mod(1994, 100), 0, 'Not a Leap Year', 'Leap Year') ),
                     'Not a Leap Year' )
                     as leap_year_indicator
from dual