The main proportion is the main sales divided by the total sales. At present, all the goods you sell are 17 (life service) +8 (clothing, shoes and bags) =25.
Main business accounts for 8/( 17+8)=8/25=32%.
In the future, if you sell more clothes and shoes, less life services or simply put the main clothes and shoes in a secondary position, you can use the following formula to calculate, in two cases:
1) Only clothing, shoes and bags will be sold from now on. If it is set to X, the main business accounts for 90%. Requirements: (8+x)/(8+ 17+x)=90%, available: x= 145; In other words, if you don't sell anything except the main business, you need 145 main businesses to reach 90%.
2) If goods other than the main business are still on sale, the situation will be more complicated. If the main business sells X and others sell Y, there is (8+x)/(8+ 17+x+y)=90%, and it can be obtained: x= 145+9y, that is, if the life service sells 65445.
Note that the premise is that at present you only have two categories: life service and clothing, shoes and bags, otherwise the situation will be complicated!
I hope I can help you.