The document lists years repeatedly in groups of 5. It asks "How old are they?" and then provides the same years as answers, except for one set where 1984 is changed to 1958. This suggests it is asking about the ages corresponding to different years.

1. HOW OLD ARE THEY?

2.  1978
 1972
 1970
 1977
 1981

3.  1978
 1972
 1970
 1977
 1981

4.  1978
 1972
 1970
 1977
 1981

5.  1968
 1962
 1960
 1967
 1966

6.  1968
 1962
 1960
 1967
 1966

7.  1984
 1952
 1960
 1947
 1956

8.  1998
 1992
 1990
 1997
 1996

9.  1988
 1962
 1970
 1969
 1976

10.  1978
 1972
 1975
 1979
 1976

11.  1979
 1972
 1970
 1977
 1975

12. ANSWERS

13.  1978
 1972
 1970
 1977
 1981

14.  1978
 1972
 1970
 1977
 1981

15.  1978
 1972
 1970
 1977
 1981

16.  1968
 1962
 1960
 1967
 1966

17.  1968
 1962
 1960
 1967
 1966

18.  1958
 1952
 1960
 1947
 1956

19.  1998
 1992
 1990
 1997
 1996

20.  1988
 1962
 1970
 1969
 1976

21.  1978
 1972
 1975
 1979
 1976

22.  1979
 1972
 1970
 1977
 1975