3 years, as 2012 was the next leap year after 2009.
There were 15 leap years in that period:195219561960196419681972197619801984198819921996200020042008
Disregarding the leap years, 17598840 hours Regarding leap years, about 17610888 hours
There were two leap years from 1999 to 2009: 2000 and 2004. Leap years occur every four years to account for the extra 0.25 days in a solar year.
From 1933 to 2012, there have been 19 leap years. 1932 was a leap year but the next one wasn't until 1936.
Just three:200020042008
There are 4 years between every leap year. Correction: There are 4 years between MOST leap years. That's the case 99.25% of the time. For the other 0.75% of the time, there are 8 years between leap years.
From 1898 until 1998 there were 24 leap years: every four years from 1904 through 1996 inclusive.
Leap years are usually every four years. They will occur every four years until the year 2096, then the next one after that will be eight years later. So since 2012 is a leap year, the next one will be 2016, followed by 2020, 2024, and so on.
16 leap years
24 leap years
Leap years occur every 4 years.
without leap years 60153 With leap years 60174