Group No. Normal Maintenance pH=4 kept for 60d pH=4 kept for 90d pH=2 kept for 60d pH=2 kept for 60d
1 4.004 3.326 2.921 2.972 2.972
2 3.810 3.014 3.231 2.948 2.814
3 3.975 3.416 3.055 3.019 3.015
4 4.001 3.259 3.202 2.896 2.581
5 4.065 3.292 3.137 3.059 3.02
6 3.930 3.481 3.051 2.488 2.873
7 3.835 3.247 3.261 2.921 2.907
8 3.457 3.443 2.777 3.090 2.879
9 3.884 3.372 3.285 3.012 2.802
10 3.995 3.426 3.066 3.014 2.96
11 3.850 3.450 3.178 3.614 2.843
12 3.825 3.345 3.292 2.989 3.019