We present the largest data base so far of atmospheric optical turbulence profiles [197 035 individual C2N(h)] for an astronomical site, the Roque de los Muchachos Observatory (La Palma, Spain). This C2N(h) data base was obtained through generalized SCIDAR observations at the 1-m Jacobus Kapteyn Telescope from 2004 February to 2009 August, obtaining useful data for 211 nights. The overestimation of the turbulence strength induced during the generalized SCIDAR data processing has been analysed for the different observational configurations. All the individual C2N(h) have been recalibrated to compensate for the errors introduced during data treatment. Comparing the results from profiles before and after the recalibration, we analyse its impact on the calculation of relevant parameters for adaptive optics.