Sentinel chicken seroconversions

October 1999
 Year Number of birds # + EEE # + SLE
 1988 na 4
 1989 na 2 81
 1990 1062 2 407
1991 794 15 23
1992 881 8 2
1993 844 1 100
1994 904 6 31
1995 1017 5 25
1996 1048 10 7
1997 1002 2 269
1998 1112 4 84
1999 1062 6 100
 Average (1998-98) 5.4 94.1
 Median (1998-98)   4.0 31.0