Your current minimum ratio is based on your downloads, (freeleech downloads are considered 'completed' but the file size of it will not be added to your download amount).
Since currently, you have already downloaded (regular download, not freeleech) 632.88 gb, that will fall under <700 gb and that is why your maintaining minimum ratio is now 0.700. Now if your regular download exceed 700 gb but under 800 gb, your maintaining ratio will be 0.750. That is how minimum ratio works.
Take for example the download size of cannonmc which is 394.09 gb which fall under the bracket of <500 gb in rationator, his minimum ratio is only 0.600 but once he exceeded 500 gb then his minimum ratio will change to 0.650 (under <600 gb bracket).
In my case, my regular download amount is only 223.03 mb which fall under the bracket of <2 gb, that is why my minimum ratio is only 0.200 but once I exceeded 2 gb download amount, my minimum ratio will change.