Many are only now realising that their experience during years of violence was not normal, Judith Thompson added.
As people age or leave the security forces and reflect on their lives they are more likely to come forward, she told MPs.
“We have a growing demand and resources which have helpfully been protected but which are not adequate to address the need for reparations, mental health, trauma support and need for ongoing services including those with physical disabilities.”
Ms Thompson gave evidence to the Northern Ireland Affairs Committee at Westminster which is investigating the work of the Commission.
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She said victims were at a critical point in Northern Ireland as the Stormont House and Fresh Start deals are rolled out to address the legacy of the past.
“The number of people coming forward for help and support as victims and survivors is increasing year on year in Northern Ireland by about 29%.
“The vast majority of those injured and traumatised and bereaved have not yet come forward. As you move further away from the experience ... in retrospect people realise that what they experienced was not normal.
“Sometimes as people get older, sometimes as they leave security services where they have been part of a very close community experience and reflect on things that they may have put to the back of their minds.”
The commissioner has been campaigning for special pensions for those unable to make their own provision for retirement due to injuries or bereavement. Around 3,720 families have been bereaved.
She said the recent political deals were the best offered for those who suffered as a consequence of the conflict.
“I do believe that on the basis of communications and dialogue this package needs to move forward.
“Trying to achieve a better consensus and understanding is a primary piece of work for the Commission at the minute.”
A Historical Investigations Unit to pursue potential prosecutions, an Independent Commission for Information Retrieval where justice is not possible and the creation of an oral history archive would be among the processes to deal with the past.
Sinn Fein has been in dispute with the British Government over part of the deal.
This month Martin McGuinness said the government must face up to its role in the conflict and deal with the legacy of the past.
Legislation sponsored by the Government on dealing with the past was recently approved by the House of Commons.