Calculate annual % change by dividing start by end value, raising to inverse years, minus one, times 100. Ex: a drop from $15M to $10M over 2 years is a 18.4% average annual decline. This calculation ...

WASHINGTON — By now we've all heard that the Pfizer COVID-19 vaccine has an efficacy rate of 95%, Moderna of 94%, and Johnson & Johnson about 66%; what you may not have known is that rate's technical ...