Ripple Burn Rate

I'm a new sign-up although I have been watching these boards for some time. Ripple interests me as it appears to be one of the few cryptos with a real world application. I found the ripple chart page https://charts.ripple.com/#/.

What I found interesting on this page and hope if someone may have clarity is the burn rate of xrp. This seems important as it will reduce the supply over time, in turn increasing the price per xrp.

Does anyone know the rate of burn of xrp per transaction?

A rough calculation indicates 5m xrp have been burnt to date. Assuming this is a linear function (which I am sure it is not) and taking xrp's start date as 2012. There is an average burn rate of 2750 xrps per day. With a current trade volume of $7.5m for the previous 24hours, this would provide an estimated burn rate of 0.000362175 xrp per transaction. A similar calculation could be applied to the number of ledgers or accounts.

Therefore, at the current rate ripple will last 99,630 years. Which brings me to my next question.

Could there the number of xrps reach zero?

Is the rate of burn the same for a transaction of 1xrp or 1m xrp?

Obviously, as transactions increase over time more and more xrp will be burnt per day. Calculating this burn rate could give an idea of future price based on uptake and daily volume of transactions.

Also, would the burn rate be linear (probably not) or follow some sort of -ln function? Surely the amount of xrp burnt would have to decrease over time otherwise it may reach zero.

It appears to be a quality often overlooked by others outside the community who complain about the huge number of xrp in existence and may explain why ripple "the company" feels the need to hold so many internally.

Look forward to your opinions. These numbers were just workout over coffee and obviously need a lot more information to get accurate results.

Maybe a chart indicating trade volume over time would lend some way to helping with this.