12

           20                   21

     6                  15            11

        7                  16      5

pre-visit:

12 20 6 7 21 15 16 11 5

in-visit:

6 7 20 12 15 16 21 5 11

post-visit:

7 6 20 16 15 5 11 21 12


pre-visit:

x 20 6 7 21 x x 11 5

in-visit:

x x x 12 x 16 21 5 11

post-visit:

7 6 20 x 15 x x x 12