Full list of non-zero Kazhdan-Lusztig-Vogan polynomials:

0: 0: 1

1: 0: 1
   1: 1

2: 0: 1
   2: 1

3: 1: 1
   3: 1

4: 0: 1
   1: 1
   2: 1
   4: 1

5: 2: 1
   5: 1

6: 2: 1
   4: 1
   5: 1
   6: 1

7: 1: 1
   3: 1
   4: 1
   7: 1

8: 5: 1
   8: 1

9: 3: 1
   9: 1

25 nonzero polynomials, and 10 zero polynomials,
 at 35 Bruhat-comparable pairs.