Fig. 4From: Imputation rules for the implementation of the pre-unification education variable in the BASiD Data SetImputationsregeln für die Generierung der Bildungsvariable in den BASiD-Daten vor der WiedervereinigungDistribution of school and apprenticeship spells by period. (Source: BASiD 2007. Notes: The figure shows the distribution of the length of school (a–c) and apprenticeship spells (e–f). School spells coded as SES = 1. Apprenticeship spells are coded as SES = 2. We close interruptions of type 1 and type 3 if the length of the interruption is less than 12 months and if the interruptions do not occur due to regular employment spells)Back to article page