As altitude increases, the available amount of oxygen to sustain mental and physical alertness decreases with the overall air pressure, though the relative percentage of oxygen in air, at about 21%, remains practically unchanged up to 21,000 metres (70,000 ft).
  State legislators in Texas (both representatives and senators) make a salary of $7,200 per year.
The Bureau of Labor Statistics reported legislators representing local towns earned an average yearly income of $37,980 in 2008, but the state's top officers made considerably more. New Jersey's top officer made an annual salary of $175,000 in 2011 and an additional $75,000 housing stipend. Governors earned an average of $130,595 in 2010. Top salaried state officials include Florida's education commissioner, with $275,000 in 2011 and Kentucky's state lottery CEO, earning $226,800.