MacBook Pro - Operating system

Hi, I have a MacBook Pro, retina 15 inch Mid 2014.

Processor: 2.8 GHz Intel Core i7

Memory: 16 GB 1600 MHz DDR3

Graphics: NVIDIA GeForce GT 750M 2 GB

Intel Iris Pro 1536 MB

At the moment I am running macOS Mojave Version 10.14.6

What is the latest operating system I can upgrade to?

Thanks very much!