#  pI = 0.39
#  pH 	   chg
  0.00	  0.00
  0.50	 -0.00
  1.00	 -0.00
  1.50	 -0.01
  2.00	 -0.03
  2.50	 -0.09
  3.00	 -0.23
  3.50	 -0.48
  4.00	 -0.75
  4.50	 -0.90
  5.00	 -0.97
  5.50	 -0.99
  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	 -1.00
  9.50	 -1.00
 10.00	 -1.01
 10.50	 -1.02
 11.00	 -1.07
 11.50	 -1.19
 12.00	 -1.44
 12.50	 -1.72
 13.00	 -1.92
 13.50	 -2.06
 14.00	 -2.24