Ohm. Because of that surface resistivity and the surface resistance are often mixed up. In order to differentiate between the two, surface resistiv-ity is often expressed also in Ohm/square (Î©/sq.) which is not a valid unit from the dimensional anal-ysis point of view. 2 Surface resistivity and surface resistance 2.1 Current density and surface cur-
The median age of the world's population was estimated to be 30.1 years in 2016, with the male median age estimated to be 29.4 years and female, 30.9 years.
Worldwide, children make up a third of the population. In 2004 there were 1,826 million children aged under 15. Only children under 15 are shown in this map and graph. Africa has the highest percentage of children.In Uganda and Niger half the population is under 15 years old.In Italy, Spain and Japan only 14% of the population are children aged under 15.n 2004 there were 1,826 million children aged under 15. Only children under 15 are shown in this map and graph. Africa has the highest percentage of children. In Uganda and Niger half the population is under 15 years old.