The new calculation is based on an evaluation of excess death data compared with current projections for deaths based on prior years of death data. The US' CDC does the same routinely and that data confirms that US COVID death data is close though underestimated.
Places like China, Iran and North Korea however will never tell the truth.
https://www.theguardian.com/world/2020/dec/28/russia-admits-to-world-third-worst-covid-19-death-toll-underreported
Follow the (gullible) science lol: