During update, system calculates (current_year-last_plague _year) and applies value to table below. If plague does reoccur, then current year becomes new last_plague_year. If last_plague_year does not exist, this routine is not run on the fief.

Years since last        Chance of               Start CNT.PLAGUERATE                            

occurrence              reoccurrence                                                            

1                       1%                      1337                    0.01                    

2                       7%                      1339                    0.03                    

3                       12%                     1341                    0.06                    

4                       18%                     1343                    0.09                    

5                       23%                     1345                    0.12                    

6                       29%                     1347                    0.14                    

7                       34%                     1349                    0.17                    

8                       40%                     1351                    0.20                    

9                       45%                     1353                    0.23                    

10                      51%                     1355                    0.25                    

11                      56%                     1357                    0.28                    

12                      62%                     1359                    0.31                    

13                      67%                     1361                    0.34                    

14                      73%                     1363                    0.36                    

15+                     78%                     1365 or later           0.39