Are “poor quality” courses in the U.K. impacting Indian students?

Only 17% of students who arrived in 2017 in the U.K got work visas, compared to 31% who arrived in 2004

Are “poor quality” courses in the U.K. impacting Indian students?
Only 17% of students who arrived in 2017 in the U.K got work visas, compared to 31% who arrived in 2004