How reliable are the figures coming out of the conflict in Ukraine?

Following Russia’s invasion of Ukraine, we consider claims about the numbers of troops involved, people killed, and planes downed.

Also: are the prime minister’s parliamentary claims about growing numbers of NHS staff backed up by data? We investigate the perplexing claim that the Chagos Islands are 100 metres below sea level. How long do you have to drive an electric car to offset the pollution from making the battery? And do we really make 35,000 decisions a day?