Which is the best estimated pressure, represented in units of gpa, of the lower mantle?

The best estimated pressure is 110 GPa. Pressures in the lower mantle begin at 24 GPa and reach up to 136 GPa at the border between core and mantle. For the most part it is composed of a single mineral called perovskite. Recent experiments show that this mineral with iron content is very unstable in the lower mantle.