13 years
There are 13 leap years during that period:2000200420082012201620202024202820322036204020442048
There have been eight (8) leap years from 1978 to 2010.(The next one is 2012):19801984198819921996200020042008
Between those years there are four.
There 400 years between them.
If you're not including 396 or 1999 but only the years between them, then there are 1999-396-1 or 1602 years
13 years
There were 1603 years between 396 CE (AD) and 1999 CE (AD).
There are 20 years between 1999 and 2019. To calculate this, subtract 1999 from 2019 (2019 - 1999 = 20). This is because you are counting from the starting year (1999) up to and including the ending year (2019), which gives you a total of 20 years.
There are 13 leap years during that period:2000200420082012201620202024202820322036204020442048
2010 - 1978 = _____
1999: there was no year 0.
That depends on the make, but not likely with that many years in between.
That depends on exactly what you mean by "between": if you want the number of whole years that are after 1988 but before 1999, that's 10 (1989, 90, 91, 92, 93, 94, 95, 96, 97, 98). If you want the number of years between, say, April 5, 1988, and April 5, 1999, that's 11.
There have been eight (8) leap years from 1978 to 2010.(The next one is 2012):19801984198819921996200020042008
Including both of those years, then it was five times. In 1982, 1993, 1999, 2004 and 2010.
1999