Reporting % 0 values for valid reads/reporting in histograms

[dataknut]

observatoryData/scripts/SERL_smart_meter_data_quality_report_v2020_08.Rmd

Line 885 in 2dd3ca3

Figure 2 excludes readings equal to 0 because there are so many that the rest of the plot is difficult to see. There is still a spike of very low reads, as we would expect from times with low light such as during winter.

It seems odd that 0 values dominate in the electricity half-hourly data? I can understand for gas (e.g. in summer). But electricity? What % are 0 Wh? Maybe this should be added to Table 7?