Opposition MPs asked ministers more than 40,000 written question in 2018, with just three National MPs contributing more than a quarter of that total figure.
National's Alfred Ngaro, Melissa Lee and Paul Goldsmith asked a combined almost 12,000 written questions over the course of 2018.
Asking roughly 4500 questions, Ngaro – National's children, community and voluntary sector and Pacific peoples' spokesman – lodged the most questions in the year.
Almost a quarter of all Ngaro's written questions were lodged on just one day.
Just 300 questions behind Ngaro's total annual question count was Paul Goldsmith, spokesman for economic and regional development. Many of his questions related to the Provincial Growth Fund.
Lee, spokeswoman for broadcasting and ethnic communities, asked roughly just over 3000.
Judith Collins, Gerry Brownlee and Todd Muller all asked roughly 2000.
National Party Leader Simon Bridges asked just 42 written questions during the year.
However, this was not unusual as Opposition leaders don't tend to ask many written questions.
On the other end of the scale, National's seniors and veterans spokeswoman Maggie Barry asked just 12 written questions in 2018.
Lee said the reason she, and National, were "very active" with their questions was because the Government would not provide straight answers.
"This Government is supposed to be open and transparent – but often one of the things I have found is the information we want hasn't been forthcoming."
She said the volume of questions stems from the responses MPs get from the ministers, which she said aren't up to scratch.
"So instead of just asking one question, I'm having to ask seven questions."
One of the biggest political stories of the year – the resignation of RNZ's Carol Hirschfeld after then-Broadcasting Minister Clare Curran mischaracterised a meeting between the pair as "informal" – came from a written question, Lee said.
She said this was "part and parcel" of why National asks so many questions.
Many written questions ask ministers what reports or briefings they have received and what meetings they have been to.
Ngaro, for example – who lodged just over 1000 questions on November 30 – asked for this information many times over to multiple MPs but lodged a separate question based on the date he was asking about.
Ngaro said the reason for so many questions was because it's "important to know what's going on" in the portfolios he looks after for National.
"It looks a little bit like a scattergun but you're actually trying to be as broad as possible," he said, when asked about the 1000 questions in one day.
He said he has five ministers he asked questions to, which was why his count was so high.
He added that part of National's role in Opposition is to ask questions of the Government to hold them to account.
Duty Minister Iain Lees-Galloway said although the Opposition has an important role in holding the Government to account, the public would have valid concerns if public resources were being wasted on answering "trivial questions and fishing expeditions".
"Just as the Opposition has a legitimate role in asking questions, New Zealanders have a right to know that ministerial resources are being spent in ways that improve the services the Government provides them."
In November it was revealed National's barrage of written questions forced the Government to hire additional staff to deal with the influx of questions.
That same month, Prime Minister Jacinda Ardern took aim at the number of written questions the Opposition had lodged.
She said in the year since the formation of the Government, MPs submitted 42,000 questions.
"That's how many we asked in three years," she told reporters at the time.
National received 19,009 questions from Labour in its first year of Government.
In 2016, Labour's last full year in Opposition, MPs asked National ministers 15,680 written questions.
That same year, senior then-Opposition MP Chris Hipkins asked 820 written questions, Phil Twyford asked 360, Jacinda Ardern asked 163 and Grant Robertson asked just 29.