A medical breakthrough causes a zombie outbreak when it mutates within certain individuals in the trial injections.
JL Major
6.0
2009
1997
5.3
2007
7.0
6.9
1994
6.4
1988
5.2
2005
5.4
5.9
1936
1974
6.2
1975
4.3
2008
5.5
1980
6.1
2018
6.3
4.8
3.2
0.0