Step 1: The variable plb0022_v1 is recoded (1=1) (2=2) (3=3) (4=4) (5 7=9) (6=11) for the year 1984 and subsequently integrated into the harmonized variable plb0022_h. Step 2: The variable plb0022_v12 is recoded (1=1) (2=2) (3=3) (4=4) (5=5) (7=7) (9=9) (10=12) for the year 2022 and subsequently integrated into the harmonized variable plb0022_h, if plb0022_v11 is -5. Step 3: The variable plb0022_v2 is recoded (1=1) (2=2) (3=3) (4=4) (7=9) (6=11) for the years 1985 to 1990 and subsequently integrated into the harmonized variable plb0022_h. Step 4: The variable plb0022_v3 is recoded (1=1) (2=2) (3=3) (4=4) (5=9) (7=9) (6=11) for the year 1990 and subsequently integrated into the harmonized variable plb0022_h, if inputdataset is "gpost". Step 5: The variable plb0022_v4 is recoded (1=1) (2 4=12) (3=2) (5=3) (6=4) (7 9=9) (8=11) for the years 1991 to 1995 and subsequently integrated into the harmonized variable plb0022_h. Step 6: The variable plb0022_v5 is recoded (1=1) (2=2) (3=3) (4=4)(5 7=9) (6=11) (8=8) for the years 1996 to 1998 and subsequently integrated into the harmonized variable plb0022_h. Step 7: The variable plb0022_v6 is recoded (1=1) (2=2) (3=3) (4=4)(6=9) (5=11) (8=8) for the year 1999 and subsequently integrated into the harmonized variable plb0022_h. Step 8: The variable plb0022_v7 is recoded (1=1) (2=2)(3=3)(4=4)(5=11)(6=11)(7=9)(8=8) for the years 2000 to 2001 and subsequently integrated into the harmonized variable plb0022_h. Step 9: The variable plb0022_h is replaced by the variable plb0022_v8 for the years 2002 to 2015. Step 10: The variable plb0022_h is replaced by the variable plb0022_v9 for the years 2016 to 2020. Step 11: The variable plb0022_h is replaced by the variable plb0022_v10 for the year 2019, if plb0022_v10 is included in that version of the questionnaire. Step 12: The variable plb0022_v11 is recoded (1=1) (2=2) (3=3) (4=4) (5=5) (6=6) (7=7) (8=8) (9=9) (10=12) (11=10) for the years 2021 to 2022 and subsequently integrated into the harmonized variable plb0022_h.