Six.
There are 90 palindromic numbers between 100 and 1000
1089
Ten
10
1089 palindromes
There are 90 palindromic numbers between 100 and 1000
18
1089
Ten
10
1089
9.5
9
1089 palindromes
25001
500
The next palindromic years are going to be 2112 and 2222. There is a 100 year difference between the two.