There was an API before they changed to that awful Microsoft product. I am not sure if the API is still running.
I found it by digging around the website. If it is still there then look and you will find it.
There is also a guy with data presentation experience who scrapes the daily figures and accumulates them into something useful. Not sure of his URL and I am busy at the moment.
The Mods apply tags to posts, if you look back through the Statistics tagged posts you will find a reference to his site.
I have all the historical data downloaded via the API and I was doing a project with a Data Scientist to get more useful information but I gave up when the Pilgrims Office went to the new website format.
I also tried, sometimes successfully, to gather data from other sources but most people are very protective of THEIR data, unfortunately. I don't understand this attitude but they hold the data and so they decide.
I am happy to share my historical data with you, it is mostly held in R tables. However I am on Camino in Spain until the end of August and the data is in Aotearoa New Zealand.
If you are interested send me a PM and once I get home I will be happy to help.