The global market

The global market for diabetes care products amounts to £27.5 billion ($41 billion). The market has grown by around 12% annually in the last decade and is expected to experience continued solid growth driven by an increased prevalence of diabetes and the need for better treatments. Of this global market, insulin accounts for 55%, oral diabetes products for 38% and GLP-1 products for 7%.

http://www.pharmafile.com/news/499362/moving-forward-diabetes

Pleas explain the use of definite article in the "the global market"

We use definite article when the reader/ listener knows about the noun- the reference to the noun is made specific

Second mention

And unique objects