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 highest-paid representatives were House Speaker Michael Madigan, D-Chicago, and Minority Leader Tom Cross, R-Oswego, who both earned $90,930. Efforts to limit legislator salaries, including votes to freeze pay and forfeit 12 days of compensation, have fallen short in the eyes of reformers.