What is the equation to convert time to percentage?

Question

Mathematics

points: eg 245000, 24500, 2450, 245, 24
time: 100%(will change)
elapsed time(in seconds): eg 3600
the more time has passed, the worse.
It is necessary to minus the points as a percentage, and the percentages will be obtained in the ratio of the time parameter.
how to write an equation so that the number of seconds (time) turns into percentages and the more seconds have passed, the smaller the percentage
is like this: 0 seconds have passed - 100%, 3600 seconds (hour) have passed - 90%, 10800 seconds (3 hours) - 75 %, 43200(12 hours) - 50%, 86400(day) - 30% and so on,
that is, the first 12 hours are important, and then the interest decreases less and less
but it’s also important to take into account the time parameter, that is, let’s say it has a value of 50%, then it’s already: 0 seconds - 50%, 3600 - 45%, 10800 - 37.5%, and so on,
please help in any way you can - sources with information about such smooth linear, examples

Answer 1

Would a parabola work? y = 100 - 100 * sqrt( x / N)(N is the time when the result becomes zero)
Approximately at your points lies a parabola with the following parameters:
(here the percentages are 1000 times greater for a proportional graph)
Or, so that the value does not fall so sharply in the first moments, you can take a shifted logarithmic curvey = 100 - 30 ln( 1 + x / 10000)