That's a somewhat ill defined question. Airline pricing has become so convoluted that "typical" is really hard to define. Yes, Google provides a chart with a number, but what exactly does that mean and is it useful ?
Prices on the same day for the same route on the same airline can easily vary by a factor of 3 depending on the desirability, demand and convenience of a specific time slot.
For connecting flights the lower fares can include self-connections, long overnight layovers, awkward routings, wonky departure/arrival times and sometimes even airport changes (example: arrive Heathrow depart Gatwick).
Additionally the airlines are obfuscating the actual price through lots of ancillary fees (seat reservation, physical check in, carry-on, checked luggage, etc.) which vary wildly between airlines. Even a moderate set of requirements (seat + carry on) can easily double the price these days.
All of this makes "typical" really hard to define. Search engines have not been able to keep up and comparing prices for "reasonable" flight options has become very tedious. That's of course what the airlines want. Fun fact: There used to be a very good website (hipmunk.com) that allowed you to sort by agony, which was a combination of price, features and convenience. Apparently that worked too well: they were bought by a large corporate travel provider and killed off. Ironically the search engine of this provider was (and still is) terrible!
Even if you define the "typical" price, the question assumes that there is a strong correlation between advanced purchase time and price. While there is some correlation, it is generally weak and swamped by other factors. For example prices in November and January tend to be cheaper than prices in December regardless of whether your buy your tickets in August, September, or October. The date of the flight is way more important than the date of purchase.
Most airlines do increase prices significantly close to the departure date (maybe one week or so) but other than that, pricing is set dynamically based on demand and it can go either way.
Anecdote #1: A company I worked for had a travel policy requiring two weeks advanced purchase for flight tickets. I argued against that and showed them many examples where this actually cost the company more money. I also asked them to provide actual data to support their claim of "well, buying early is cheaper". They couldn't provide it. Of course, they didn't change the policy but at least they stopped dinging me for violating it :-).
Here is another data point to consider: If you look at crowd sourced forums and websites that show "great deal" for flights (such as flyertalk.com), there is almost no correlation to the departure date. It's mostly an even mix of "this week", "a few months", "next year".
Anecdote #2: About a year ago, I monitored prices from the US east coast to New Zealand for travel in Feb 2023. Prices were high, around $2000. Then, out of the blue, they dropped to $900. Apparently these tickets went fast so a few weeks later it popped back up to $2000. Buying in September cost $2000, buying in October $900 and in November its $2000 again. There is no way to predict this.
