Hi
Marsha
Hope this is right and makes sense.
The graph shows the percentage of people being tested who test positive for either the “new variant or others”.
So for example, in London, in the middle of the graph, just after 26th December, about 4% of people who were tested were positive (3% new variant , 1% other variants ). As a fraction of positive tests new variant accounted for 3/4.
Now it has reduced (as has the total number of people testing positive).
On 16th January, about 3% of people who were tested , tested positive (2% new variant, 1% other strains). As a fraction of positive tests the new variant now only accounts for 2/3.