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.
Quick Answer. In the House of Representatives, states are represented according to their populations, with each state guaranteed at least one representative. The total number of representatives is capped at 435 as of 2014, so states gain or lose representatives according to population shifts. Continue Reading.