计算特定范围/列Excel中的非空行

I want to count empty (or non-blank) rows in a given column (or range). Example: I have a column which is spaning over 4 cells width, and each cell has either a single ''x'' or is empty. There is up to 100 rows under this column. Here's a picture to clarify:I want to count empty (or non-blank) rows in a