“Age band” rate tables can be input “longhand” to excel spreadsheets as lookup tables. For example, the rate table;

Age rate
<50 0
51 to 55 0.1
56 to 60 0.2
61 to 65 0.3

can be input as

Age rate
16 0
17 0
18 0
19 0
20 0
21 0
22 0
23 0
24 0
25 0
26 0
27 0
28 0
29 0
30 0
31 0
32 0
33 0
34 0
35 0
36 0
37 0
38 0
39 0
40 0
41 0
42 0
43 0
44 0
45 0
46 0
47 0
48 0
49 0
50 0
51 0.1
52 0.1
53 0.1
54 0.1
55 0.1
56 0.2
57 0.2
58 0.2
59 0.2
60 0.2
61 0.3
62 0.3
63 0.3
64 0.3
65 0.3