Count occurrences of a value

On the attached worksheet i have data in cols A&E arranged by date and time & related data in col AK.
From col AK i wish to count the number of digits less than 3 in each block,the results being given in col BA.
Is it possible (without using a pivot table) to construct a formula not restricted in the number of rows to achieve this.Some cells in AK are blank,I have inserted empty rows between the blocks for clarity,there are no empty rows in the data.
Many thanks for help given.

You could try =COUNTIFS(E:E,405,AK:AK,">0")
Just change the 405 for required number.

Windy

Thanks for the reply windy58.
Correction .My original post should read number of digits less than 4 for each block in col AK.