trigger not working help :(

[AlexSchezar]

so am making a map where every 25 kills you get one probe but the way iv done the trigger once you get 25 kills it just spams probes here the trigger i used

player 1 kills extracly 25 of any unit

create 1 protoss probe at spawn chooser here for player 1.apply properties
preserve trigger

i dont want i to spam probes i only want to have 1 probe every 25 kills please help