Great question, especially for those of us in the "never burn bridges" space.
My empirical data (i.e.: non-scientific - just a guess) is that the distribution is an inverted curve, with higher occurrences at the extremes between longer times, and shorter times.
On the longer time side: With perhaps 15% of those "experienced" (ex: not obvious noob) POT's who engage with me to the point of exchanging phone numbers I find an old text chat on my phone. Typically, she's using a new profile and some or all new pics. I've seen this happen with POT's I originally texted up to 2 or more years ago. Of course, I re-read the whole chat string before I reply.
In most of these cases, the last 4 or 5 messages show the reason why we stopped: usually due too much daylight between allowance values, or some key deal-killers on BCD specifics.
On the shorter time side: With GPS POT's and scammers (the whole gamut of catfishers, Pig Butchers, and local cash & dash artists) I'd say they change numbers as often as they change pimps, which may be the actual reason they get a new number. LOL Even here, they say or send something that triggers the connection to our last chat. I always download all profile pics for POT's that I message or who message me. I file them under their profile name and the date I saved the pics. In one case, I saw a recycled POT profile that used all different pics, but they appeared to be taken at same time as her original pics. For example, a pic of her sitting in an expensive car, only in a slightly different position. I recognize the car and the girl and can easily make the connection to her older profile.
Life is good
The Cat