SQL - How to find optimal performance numbers for

First time here so forgive me for any faux pas. I have a question about the limitation of SQL as I am new to the code, and what I need I believe to be rather complex.

Is it possible to automate finding the optimal data for a specific query. For example, say I have the following columns:

1) Vehicle type (Text) e.g. car,bike,bus

2) Number of passengers (Numeric) e.g. 0-7

3) Was in an accident (Boolean) e.g. t or f

From here, I would like to get percentages. So if I were to select only cars with 3 passengers, what percentage of the total accidents does that account for.

I understand how to get this as a one off or mathematically calculate it, however my question relates how to automate this process to get the optimum number.

So, keeping with this example, say I look at just cars, what number of passengers covers the highest percentage of accidents?

At the moment, I am currently going through and testing number by number, is there a way to 'find' the optimal number? It is easy when it is just 0-7 like in the example, but I would naturally like to deal with a larger range and even multiple ranges. For example, say we add another variable titled:

4) Number of doors (numeric) e-g- 0-3

Would there be a way of finding the best combination of numbers from these two variables that cover the highest percentage of accidents?

So say we took: Car, >2 passengers, <3 doors on the vehicle. Out of the accidents variable 50% were true

But if we change that to:Car, >4 passengers, <3 doors. Out of the accidents variable 80% were true.

I hope I have explained this well. I understand that this is most likely not possible with SQL, however is there another way to find these optimum numbers?

Thanks in advance

Here's an example that will give you an answer for all possibilities. You could add a limit clause to show only the top answer, or add to the where clause to limit to specific terms.

SELECT
    `vehicle_type`,
    `num_passengers`,
    sum(if(`in_accident`,1,0)) as `num_accidents`,
    count(*) as `num_in_group`,
    sum(if(`in_accident`,1,0)) / count(*) as `percent_accidents`
FROM `accidents`
GROUP BY `vehicle_type`,
    `num_passengers`
ORDER BY sum(if(`in_accident`,1,0)) / count(*)