Enemy Spawn faster

Hello, I have been stuck here for a bit,
I made a timer function in my gameModeClass, and it calls to an actor (spawner), and here is when my enemy blocks spawn. The problem is, the game is too repetitive as the enemy falls at the same rate throughout, so i wanted to make it so that after some time the enemy fall at a faster rate, or more spawn.
I tried making the Time a variable and had other classes call it to increase in number (1/1, 1/2, 1/3) overtime gets faster, and planned on adding a clamp to limit, but when i did this it did not work.
I later simply tried to subtract a minuscule amount every loop but although i used a string function, and the variable’ did decrease, the enemy still fell at the same rate.

How can i go about it so they fall faster over time.
I am trying to make it like subway surfer, except instead of the speed increasing, the enemy spawn rate does.
Thank you.

Many ways to do it, here’s one:

Hope the comments are self-explanatory, do tell if they’re not.