Why are readily available productivity data relative, not absolute?
The data you ask for is in the OECD stats website under


  Productivity > Productivity and ULC – Annual, Total Economy > Level of GDP per capita and productivity


This is the graph (in 2010 PPP US dollars):



Aternatively, you can compute it manually:


Select a series of constant GDP of your interest. 
Divide it by number of hours for a group of interest.


You can find both series in the above website. GDP is under 


  National Accounts > Annual National Accounts > Main Aggregates > Gross domestic product 


Hours are under


  Labour > Labour Force Statistics > Hours worked