Property Observer not related with terrorize function of fredTheZombie

Page 197: Why The population has changed to 1005412 from 1005422. (line 3) is printed before line 4: “Monster is terrorising a town”?

How can we fix that? when the Zombie is terrorizing town the correct printing order should be:
Firstly -> "Monster is terrorizing a town"
Secondly -> “The population has changed to 1005412 from 1005422”