#pI = 3.73
#  pH     chg
0.00     1.00
0.50     1.00
1.00     1.00
1.50     0.99
2.00     0.96
2.50     0.88
3.00     0.67
3.50     0.24
4.00    -0.30
4.50    -0.70
5.00    -0.89
5.50    -0.96
6.00    -0.99
6.50    -1.00
7.00    -1.01
7.50    -1.03
8.00    -1.09
8.50    -1.23
9.00    -1.48
9.50    -1.75
10.00   -1.90
10.50   -1.97
11.00   -1.99
11.50   -2.01
12.00   -2.04
12.50   -2.13
13.00   -2.32
13.50   -2.61
14.00   -2.91