Counting number of days it takes to reach desired value

Hello,

I've been working with some spreadsheets but I can't figure out how to do this one formula I need. I'm trying to count how many cells (Blank & Non Blank) it takes until a certain value is reached. In this case I'm trying to count how many days it takes to reach 80% or the first value above 80%. But I dont want any value to be returned unless the data set has reached 80% because I am updating the spreadsheet daily and some of the entries have not reached 80% yet, but they eventually will as time goes bye. I was trying to use a countif function but I'm not really sure what to use. All of the data for the function is in one row.

Thank you for the help, it would be much appreciated!

Rob

Okay so I'm trying to get row "G" based on the data to the right