What formula can i use to solve for 66%

In this scenario i am using the high for 99% and the low for the 33% but i need to find the 66%. Is there any way to solve for this.

Open High Low Close $ 3,131.25 $ 3,136.25 $ 3,131.25 $ 3,131.25 99% $ 3,136.25 66% 33% $ 3,131.25 Open High Low Close $ 3,131.25 $ 3,136.25 $ 3,131.25 $ 3,131.25 99% $ 3,136.25 66% 33% $ 3,131.25