I have a sheet with statistical data values in range(C9:AM14)
With each row the values will generally descrease in value
Each row has a Date placed in cells B9:B14 to indicate when the data was collected in that row
Not all cells require values in them, so i need to ignore empty cells if there are some

I have a value in AD8 which is the LOWEST value required

What i want to do is have a prediction formula done, so that based on the VALUES in C9:AM14 i get a
Date Value when at least 20% of the values will decrease to the AD8 value


Sheets is like :

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A B C D E F G H I J ---
AD ----AM AN AO AP
1
-
8
0.5
9 1/1/05 10 10 10 10 10 10 10 10 10 10 10
10 10 10
10 1/6/05 9 9 9 9 9 9 9 9 9 9
9 9 9 9
11 1/1/06 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5
7.5 7.5 7.5
12 1/6/06 6.1 6.1 6.1 6.1 6.1 6.1 6.1 6.1 6.1 6.1 6.1
6.1 6.1 6.1
13 1/1/07 5.5 5.5 5.5 5.5 5.5 5.5 5.5 5.5 5.5 5.5 5.5
5.5 5.5 5.5
14 1/6/07 4.2 4.2 4.2 4.2 4.2 4.2 4.2 4.2 4.2 4.2 4.2
4.2 4.2 4.2
-

I want a formula to say give me a date when 20% or greater of the values will be less than or equal
to AD8(0.5)

I got no idea how to get this from the data.

Corey....