I am not quoting the OINP example but I prepared documents for the last 10 yrs of work exp for EE application... I understand that you require to show 5 years of work experience for OINP, please correct me if I am wrong..
I had work contracts tucked into my file, along with the salary increment letters etc... of these last 10 yrs...
Tough one was, I had to work hard to get the Reference letters out from my previous organizations(I had worked for 3 different companies in these last 10 yrs), but they all supported me.
Between Jan'08 - Jul'11 I worked for a company, but never stored any pay slips neither I had any bank statement available from these years. So my justification ended up coming in the form of a End of Services Benefits letter when I left this company.. which had my base pay, my bonus, number of years and days that I worked...
So can you find something with regards to work docs that can build your story... incase you are not able to do, you may have to write an explanation, why you cannot produce this...