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.
Politicians in the Executive branch earn much more than those in the Legislative branch. The average annual salary of a State Legislator is $50,000, besides the per diem rate of up to $200 for each day they are in session.