Clamping how fast a Float can change between -1 and 1

Let’s say my Input X float changes in a amount of time from -1 to 1 (-1, -0.5, 0, 0.5, 1) so as an example the speed is 12 (Which I calculate by subtracting the current input from last input and dividing that by World Delta Seconds which will result in the Speed of change).

Now the float changes quicker, so from -1 to 1 (-1, 0, 1) so now the speed is 24, right?
But I want a way that if it the input speed from InputX exceeds the example speed of 12, that the InputX speed still changes at the speed of 12.

I tried for days but I have no idea what to do anymore.