This data-set records the jittered locations of farms in Cornwall whose herds
tested positive for bovine tuberculosis during the years 1989 to 2002. The jittering 
(random perturbation) has been used to preserve confidentiality. This has the effect
of moving the underlying point process  (very slightly) towards a homogenoeus Poisson 
process.

File BTB_jittered.txt has three columns, corresponding to (x,y)-coordinate and year

File BTB_poly.txt is a digitised bounding polygon for the data that approximates the
boundary of Cornwall.