How can I fix an issue with Excel Reader writing values in column as missing

I'm reading an Excel file using the Excel Reader. The reader works well for all fields except one. It consistently marks all the values in a particular numerical column 'Number of meters' (column G of each sheet) as missing. The file is open data but a copy has been attached for convenience: https://www.gov.uk/government/statistics/lower-and-middle-super-output-areas-gas-consumption