I am suprised who weak doctors are in Math! You don't need to be a Math genius to grasp this: initially, they were testing symptomatic people, mostly people with high fever, and we know not all develop fever. So, now, testing has opened up to more people, i.e. asymptomatic and with mild symptoms. It's beyond obvious that CFR will drop! CFR will always drop with time - unless the virus mutates and becomes more severe. Also, many dilute the mortality with some unreliable antibody tests, which also are not randomized samples. In the Balkans, the antibody tests show very low infection rate, yet, the epidemic has effectively stopped - more than 2 weeks after the restrictions got removed. Obviously, the Summer weather is helping, but this also means that, for sure, there will be a second wave in the Fall as infections are still growing and in some areas they are literally just in the beginning.