This is the 'difficult' version of the simple substitution cipher.
It is worth 30 points. In addition, the first solver gets an
addtional 15, second and third get an additional 10 and the fourth
solver gets 5. There are also 5 bonus points for the first person
to identify the significance of the plaintext (where did it come from?)
UHAAEHIU%%JBCZYVJ%ZAL'%ZA%CYIJBCZYEYWJI'%%YUC+ASCG-ABY
EYHSYY%UBECZJSCYYBFJBDCY%BASCZ-YU%CUBEVGBASCZFUJBVSUBKZ
%YWYBCZIJFVYU%C%JEY%ZAAC+SAFCZYIY+CYGYA+CZYEYUCZ'%ZYUE
UVYYIJBY+SAFCZYCSYYCZSADHZCZY%ZAC+J+CG+YYCADC