Defining a "world leader" as the president/prime minister/highest-ranking official of a country, beginning January 1st 2023 and ending if someone is assassinated, or a world leader that is in power as of January 1st 2023 but later steps down. Assassination is either definitive (e.g. someone is shot on live TV) or a situation where there is a general consensus of experts/an UN body/some other indisputable evidence there is foul play (e.g. someone falls out a window).