My plant is two years in a large pot and the leaves are turning yellow and shedding leaves.
If you see roots sticking out of the drainage holes of your pot, it's a good indicator that you will need to repot your plant.
Choose a container that is just 1 or 2 inches larger then the current container, with good drainage holes.
Use a good quality commercial potting mix.
Yellowing leaves can indicate a watering issue, environment, pests and disease.
These articles will help you.