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.
Legislative Salaries. Illinois' lawmakers each earn a base salary of $67,836 a year, making them the fifth-highest-paid state legislators in the country behind those in California, Pennsylvania, New York and Michigan. But compensation for being an Illinois senator or representative doesn't end with base salary.