According to the 1985 Science Citation Index, the following members of British University Psychology departments had 60 or more journal citations (The number of citations are in parenthesis):

Argyle, J. M.  (170)      Furnham, A.F. (62)       Trevarthan, C.B. (73)

Booth, D. A.  (101)      Giles, H. (71)               Trimble, M.R. (97)

Braddick, O. J. (83)     Gray, J.A. (251)            Venables, P.H. (68)

Bower, T.G.R. (85)       Lee, D.N.(84)              Warr, P.B. (120)

Coltheart, M.  (164)     Mackintosh, N.J. (176)  Warrington, E.K. (180)

Cooper, S.J. (82)         Robbins, T.W. (69)       Weiskranz, L. (64)

Eysenck, H. J. (813)     Rolls, T.W. (61)           Wilson, G.D. 984)

Eysenck, M.W. (90)      Sandler, J (97)             Yule, W. (60)

Eysenck, S.B.G. (91)    Shaffer, H.R. (67)

Below is the graph of these data. Explain the distribution of these data and the reason why the data are distributed this way.