The only explanation that fits as far as I am concerned is that (as has now been shown to be true in the UK), WC saw many infections that came from all over the Wolrd ( UK and EU mainly), from as early as November last year. throughout the summer holiday tourist season.
Then cam the official reports, the closing of international travel, and the testing associated with that. Those infections were found shut down and controlled. Meanwhile, in the background, the real killer cells were working away.
Unfortunately, there was no monitoring going on then and no data collection in place. People were not necessarily getting very sick. If there were deaths, they probably disappeared into the normal death figures.
This is quite an interesting report to look at, but it only starts in March 2020.
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The same plot for GP. The scale is different and the pattern of the spread is completely different for GP
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