How is a wild Pokemon's level determined?

In Bulbapedia you can see there’s many occasions where the same species of Pokemon in one grassy area can appear in different levels and whenever I grind in one area I always see that most Pokemon have a certain level range and the ones with lower levels are more likely to appear than with higher levels. My question is is there a specific chance for each level in the range? Say the level range is 25-28 but the chance of getting a lv 25 is 50% then for a lv 26 it’s 10% and so on. I tried to look for a chart or something and couldn’t find anything but I have seen a youtuber who said “If you use a lv 37 repel trick in the Safari Zone there’s a 16.66% for a Houndour and an 83.33% for a Miltank” but I don’t know how he got the numbers. Right now I need this for Gold but information for any gen would be appreciated.

Pleaselog inorregisterto add a comment.

Pokemon games use something calledencounter tables. Each area and time of day/season has its own table of the Pokemon that occur. (Sun/Moon even has separate tables for every patch of grass in one area too!)

Each table is made up of severalslots, and when you encounter a Pokemon the game chooses a slot at random for the area you’re in. But each slot has a different percentage, so some Pokemon appear mroe than others. The slots are the same for every table in a game but they have different Pokemon of different levels in them.

For example, in Sun/Moon there are 10 slots in each table with percentages 20%, 20%, 10%, 10%, 10%, 10%, 10%, 5%, 4%, 1%. If there was only 1 Pokemon in a route then it would have the same thing in all slots. But each slot could have a different level e.g.

Yungoos L2 (20%), Pikipek L2 (20%), Yungoos L3 (10%), Pikipek L3 (10%), Yungoos L2 (10%), Pikipek L2 (10%), Rockruff L2 (10%), Rockruff L2 (5%), Rockruff L2 (4%), Mareanie L3 (1%)

So here you can see Yungoos level 2 has a 30% chance to appear, while Yungoos level 3 has a 20% chance to appear. Same for Pikipek. But most guides just give the overall percentage, e.g. Yungoos level 2-3 has a 40% chance to appear.