The fall comes amid concerns about specialists preferring to work in private hospitals rather than public ones, and cuts to hospital funding.
The AIHW data, to be released on Wednesday, stated that these surgeries fell from 3025 in 2012/13 to 1514 in 2022/23.
This type of surgery peaked at 3256 in 2018/19.
The hospital performed 1861 non-urgent surgeries in 2021/22, 19 per cent more than 2022/23.
AIHW spokesperson Clara Jellie said public hospitals had made "concerted efforts to work through procedures delayed when non-urgent surgeries were suspended [in the pandemic]".
"But because of these delays, overall waiting times for people admitted for care have increased," Ms Jellie said.
Hunter New England Health said it doesn't comment on AIHW data.
However, it made a submission last month to the special commission of inquiry into healthcare funding in NSW.
The submission noted that the "Collaborative Care program was initiated in 2020 to address elective surgery backlogs during the pandemic".
This involved private hospitals doing surgeries under contract with NSW Health.
"The unintended consequence of the program saw workforce issues exacerbated by increasing private sector services, leading specialists to prefer private over public employment," HNEH chief executive Tracy McCosker wrote in the submission.
"As a result, we are finding it difficult to recommence elective surgery at our full internal capacity now that collaborative care will end on December 31, 2023."
Ms McCosker added that "recruiting and retaining health workers - particularly medical specialists, nurses and midwives and allied health professionals - pose significant challenges".
AMA NSW president Dr Michael Bonning said the organisation was "deeply concerned by cuts to hospital funding, which have an inordinate impact on hospitals like John Hunter which deal with a significant case load of trauma patients".
"Much of the acute trauma between the Queensland border and north of Gosford is managed at John Hunter Hospital," he said.
"The need to address acute trauma has impacted the ability of the hospital to deal with elective and non-elective surgery.
"Funding is urgently required to avoid elective surgery cancellation due to lack of theatre space."
As for semi-urgent elective surgeries at John Hunter, they rose by 3 per cent from 2021/22 to 2022/23.
However, looking at the longer term, the number of these surgeries fell 24 per cent from 2934 in 2012/13 to 2234 in 2022/23.
This type of surgery, which includes toe or finger amputation, craniectomy and small intestine endoscopy, peaked at 3598 in 2016/17.
Semi-urgent elective surgery is recommended within 90 days.
Urgent elective surgery rose by 11 per cent from 2735 in 2021/22 to 3041 in 2022/23.
But the latest figure represented an 8 per cent fall in surgeries when compared to 2012/13.
This type of surgery, which includes heart valve replacement, melanoma excision, limb amputation and stone removal from the urinary tract, peaked at 3299 in 2012/13.
Urgent elective surgery is recommended within 30 days.
The AIHW also released data on the percentage of patients who received their surgery within clinically recommended times at John Hunter.
Non-urgent elective surgery fell from 85 per cent in 2021/22 to 64 per cent in 2022/23.
Semi-urgent elective surgery fell from 85 per cent in 2021/22 to 63 per cent in 2022/23.
Urgent elective surgery was 100 per cent in 2021/22 and 2022/23. In seven out of the last 10 years, this figure was 100 per cent.