What is the meaning of the expression…
PART OF THE WAY THROUGH?

Definition:

used to describe what fraction (or percentage) of something is complete

Examples:

• I am two-thirds of the way through my book.
• He is three-quarters of the way through his research project.
• I am one-half of the way through my university degree.
• He is halfway through his dinner.

Notice the difference in structure when you use halfway versus other amounts.