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.
For instance, Michigan State Senators earn an annual salary of $79,650 per year, plus a $12,000 yearly expense allowance, which lifts their annual pay rate up to $91,650. That is quite a difference, in salary comparison, to Georgia State Senators.