I have a sheet that looks something like this:

Sheet 1

    1   2   3   4   5   6   7   8   9   10  11
1                                           6
2                                       3   5
3                                           
4                               2   4   9   4
5                                           
6                                   4   6   6
7       5   3   3       3   10  8   4       8
8                                           
9                           4   11  12  12  6
10                                          
11  8   5   5       4   9   4   7   6       

What I would like to be able to do is find the average difference and direction between values in each column. For example, the first 4 rows would look like:

     Average Difference # + Movements   # -Movements
1           
2           2                    1              0
3           
4       (2+5+5)/3                2              1

Blanks represent N/A values due to insufficient information, and differences are calculated successively i.e. col2-col1, col3-col2, col4-col3

If I just take the differences and make a duplicate table with the formula =C2-B2 copied across issues arise whenever there is a blank space between two values or at the beginning of the row. Is there an easy way to fix this or another way to do this that I might be missing?