"They are starting their lives deeper in debt than ever before."
The average debt of a student leaving university with a bachelor's degree was almost $24,000.
Mr Hughes also said the parliamentary library had provided figures to him which showed that the Consumer Price Index had increased by 11.7 per cent since 2009, but the tertiary education component of the CPI had risen by 31.7 per cent in the same period.
One of the sets of figures released yesterday suggests there may be some significant shifts in the economic advantages of tertiary study.
From 1999 to 2003, the increases in income of student loan borrowers between their first year of earning and five years later was over 50 per cent, and 49 per cent in one year.
From 2004, the increase has been 41.4 per cent, 37.7 per cent, 35.9 per cent, 31.7 per cent and 30.2 per cent.
According to the 2014 Student Loan Scheme Annual Report, $14.23 billion is owed and the medium repayment time of those who left study in 2011 and stayed in New Zealand was expected to be 5.8 years.
Tertiary Education Minister Steven Joyce said while course costs had gone up faster than living costs, the overall amount people were leaving with had gone up 9 per cent compared with the CPI of 11.7 per cent.
Mr Joyce said while overall student numbers were down, rising course costs were not the reason.
An economic upturn always sent more people back to full-time work from study. Number studying peaked in around 2009 to 2011.
Another reason for fewer students was that a demographic bubble of 21 year-olds had gone through the system.
He also said there was an ongoing decline in low-level study. The number of 18 to 24 year olds studying for a degree peaked in 2013.
Who, what and how much
• A total of 191,958 students - 46.1 per cent of tertiary enrolments - took out student loans in 2013.
• A total of 83,200 students - 20 per cent of tertiary enrolments - received accessed non-repayable student allowances in 2013.
• New student loan borrowers in 2013 totalled 50,028.
• The average amount borrowed in 2013 was $8440, an increase of 18.4 per cent over five years.
• The average allowance paid in 2013 was $6850, compared with $6690 in 2009.
• The average student debt on leaving study was $16,900 in 2012, compared with $14,880 in 2008.
• The average debt on leaving with a bachelor's degree was $23,700 in 2012.
• Loans were fully repaid in March following the last year of study by 29.2 per cent in 2012.