# pI = undefined
#   pH    chg
  0.00	 -0.00
  0.50	 -0.00
  1.00	 -0.01
  1.50	 -0.03
  2.00	 -0.08
  2.50	 -0.21
  3.00	 -0.46
  3.50	 -0.73
  4.00	 -0.90
  4.50	 -0.96
  5.00	 -0.99
  5.50	 -1.00
  6.00	 -1.00
  6.50	 -1.00
  7.00	 -1.00
  7.50	 -1.00
  8.00	 -1.00
  8.50	 -1.00
  9.00	 -1.01
  9.50	 -1.02
 10.00	 -1.05
 10.50	 -1.15
 11.00	 -1.36
 11.50	 -1.68
 12.00	 -2.00
 12.50	 -2.33
 13.00	 -2.65
 13.50	 -2.86
 14.00	 -2.95