# pI = 3.97
#   pH     chg
 0.00	  2.05
 0.50	  2.01
 1.00	  1.98
 1.50	  1.93
 2.00	  1.81
 2.50	  1.52
 3.00	  1.07
 3.50	  0.52
 4.00	 -0.03
 4.50	 -0.49
 5.00	 -0.79
 5.50	 -0.93
 6.00	 -0.98
 6.50	 -0.99
 7.00	 -1.00
 7.50	 -1.00
 8.00	 -1.00
 8.50	 -1.00
 9.00	 -1.02
 9.50	 -1.05
10.00	 -1.14
10.50	 -1.38
11.00	 -1.79
11.50	 -2.27
12.00	 -2.66
12.50	 -2.87
13.00	 -2.96
13.50	 -2.99
14.00	 -3.00