How to count non-digital content and calculate the percentage

"施工中"To be improved  =100/4

"完成"complete =100/2

How to count non-digital content and calculate the percentage?

How should I modify the following formula?

let myfield1 := if text('主浴檯面狀態') = "完成" then
100 / 2 end;
let myfield2 := if text('公浴檯面狀態') = "完成" then
100 / 2 end;
myfield1 + myfield2