Reference data you can use, relative Shore values.

SHORE HARDNESS SCALE COMPARISON

 
Shore A
0
10
20
30
40
50
60
70
80
90
99
                   
Shore D 0 10 20 30 40 50 60 70 80 90 99
                   
Shore 00 0 50 60 70 80 90 99
           
-erasers-   -o-rings- -plastics-