Help with Database

I want to make a report of the backup health and frequency of all clients over time.
UrBackup Web GUI shows only the current status, but does not show historicals, nor let me make a report on them.

So, I opened the backup_server.db SQLite DB and took a look at the data.

The table clients_hist seems to have the historical, so I filtered the field last_seen for one particular client.
This client is up and running 24/7, at least for the last month, on the same LAN, but the db only show details for the last few days, after that I see only daily historical information.

My client is set by default (file backup every 5 hours), but I see the “last_seen” with less and less details as I go back in time, just a few days.
I was expecting to see many entries on last_seen for a particular client, and next to it, the time of the latest backup at the particular time the client made contact (which should be every 5 hours)

Is the DB purging the historicals?
Thanks

Adding more to the same question:
I noticed that the table client_hist keeps details on “last_seen” column for the last week only, meaning that I see 5 entries on “last_seen” for each client, per day.
After that it keeps only daily, so I see 1 entry on “last_seen” for each client, per day.

I guess if I could find a way to make the database keep details for a month, it would be great.
Can we alter a setting to achieve that?

Again, adding more:
Yes, seems the historical entries for backups older than a week (or around 5 days I think), are been deleted from the database.
(not the backup themselves, just the entries on the DB, which is strange because the GUI shows the list of backups, with the detailed timestamp, for older backups). Maybe that DB moves those records somewhere else or what the GUI is showing is the timestamp directly from the folder structure.
In any case, I put a script that copies the data from clients_hist table onto a new table on another DB, and I run the script via cron every day, so my new table always has the details now, and I will make my reports from it.
I accomplish what I needed, but with an extra step, but it would be interested to know why the clients_hist purges the old entries.