Question about the dynamic block count in a data extraction table

I made a floor plan that consisted of 28 floor panels that I placed in the drawing as an array of dynamic blocks. They are arranged in four rows of seven. This obviously totals 28 panels. I then performed a data extaction using the data extraction icon on the Linking & Extraction panel under the Insert tab. I only checked the boxes that would give me a count of the floor panel blocks I mentioned. For some reason I get a count of 29 for the number of floor panels. I have attempted this four times with four different floor panel blocks with slightly different names. Does anyone have any suggestions where the extra panel in the data extraction table came from?

Incidentally, I also eperimented with adding a couple extra blocks to my drawing after already doing the data extraction and making the table. I thought that the table would automatically increase the count of floor panel blocks by two, but nothing happened. Can anyone advise how to make the table update when you change a drawing.

try RE to regenerate the table

also - are you sure there are 28 objects? select one and select similar (ctrl+shift+A) and check properties (CH).

sorry if these responses are too basic for you!