Using LINEST function on Dynamic Series

Hi

I have developed a dynamic chart so that the data is plotted correctly even if there is data missing in the selected series. I want to use the same data and LINEST function to calculate the Slope of the line with zero intercept. I have used the SLOPE and INTERCEPT functions on the same data and I get correct but when I use the LINEST function it gives me error #VALUE.

Could someone help me to calculate the Slope of the line with zero intercept. Please see the attached spreadsheet.