It takes the Earth one year to orbit the Sun and it takes Mars about 1.9 years (say 2 years for easy calculation) to orbit the Sun. The elliptical orbit which carries you from Earth to Mars is longer than Earth's orbit, but shorter than Mars' orbit.
Equity theory was first developed in 1963 by John Stacey Adams, a workplace and behavioral psychologist, who asserted that employees seek to maintain equity between the inputs that they bring to a job and the outcomes that they receive from it, against the perceived inputs and outcomes of others.
As a result, it is a good idea to examine the drivers of ROE. In order to do that, E.I. du Pont Nemours and Company came up with a system to deconstruct ROE. Over the years, this system has become known as the DuPont model. The DuPont Corporation created its method for analyzing return on equity in the 1920s.