Find out the names of people who have held the position of secretary general in the past and list them with the dates of their tenure and the country of their origin?

The following individuals have served as Secretary-General of the United Nations:

1. Trygve Lie (Norway) - 1946 to 1952
2. Dag Hammarskjöld (Sweden) - 1953 to 1961
3. U Thant (Burma, now Myanmar) - 1961 to 1971
4. Kurt Waldheim (Austria) - 1972 to 1981
5. Javier Pérez de Cuéllar (Peru) - 1982 to 1991
6. Boutros Boutros-Ghali (Egypt) - 1992 to 1996
7. Kofi Annan (Ghana) - 1997 to 2006
8. Ban Ki-moon (South Korea) - 2007 to 2016
9. António Guterres (Portugal) - 2017 to present

This list includes the names, their tenures, and their countries of origin.