As most of earth's land is in the Northern Hemisphere only 4 countries are wholly south of the "Tropic of Capricorn" which are Eswatini, Lesotho, New Zealand and Uruguay. This contrasts with 74 which is about one third of the current total, wholly north of the Tropic of Cancer.

A circle of latitude on Earth is an abstract east–west circle connecting all locations around Earth at a given latitude. There are 5 major circles of latitude from north to south. The position of the Equator is fixed (90 degrees from Earth's axis of rotation) but the latitudes of the other circles depend on the tilt of this axis relative to the plane of Earth's orbit, and so are not perfectly fixed.

The values below are for 29 March 2020, Arctic Circle (66°33′48.0″ N), Tropic of Cancer (23°26′12.0″ N), Equator (0° latitude),Tropic of Capricorn (23°26′12.0″ S), and Antarctic Circle (66°33′48.0″ S).

"The Tropic of Capricorn" marks the most southerly latitude at which the sun can appear directly overhead. This happens at the December solstice, when the southern hemisphere is tilted towards the sun to its maximum extent. Less than 3% of the world's population live south of "The Tropic of Capricorn".

Starting at the Prime Meridian and heading eastwards, the "Tropic of Capricorn" passes through these 10 countries namely Namibia, Botswana, South Africa, Mozambique, Madagascar, Australia, Chile, Argentina, Paraguay, and Brazil.

More Info: en.wikipedia.org