Calculating value for maximum consecutive value

Hi

I use MS 2007. I try to create formula to find the average of maximum consecutive value. According to my sample, I would like to get the average of maximum consecutive value from range a:p ;

PHP Code: 

To give more idea, the example is
         a  b  c  d  e  f  g h  i   k  l  m  n  o  p               q             r
firm                                                                maxyr       avr
xxxx   1   2  0  0  5  2  3  9 0  0  0  3   4 5   0                 4         (5+2+3+9)/4
xxxy   0   0  0   4  3 0  0  0 4  5  0  0   0 0   0                 2         ((4+3)/2) +((4+5)/2)
xxxz   0   5  2   4  5 3  0  0  0 6  7  0   0  0  0                 5         (5+2+4+5+3)/5 


How to get the formula for column r? Any help will be appreciated.

Note: I also attach my original excel file. In this original file, I would like to get the formular for column AM (AvrMx)