New Delhi, June 14 -- Almost one in three persons tested for the coronavirus disease (Covid-19) in Delhi this week had the infection, according to government data. The average positivity rate - the percentage of people who test positive - in Delhi during the week was 30.5%, a number that is perhaps as indicative of the inherent bias in testing (which has only become more marked, especially in Delhi) as it is of the spread of the pandemic in the capital....