Table 1. Sample size per decade and the probability of detecting no Bd based on a 5% conservative probability of Bd detection.

Credible intervals (CI) were calculated using binomial confidence intervals.

Time Period	Negatives	Positives	n	Lower CI	Upper CI	Pr
1900–1949	235	2	237	0.1	3.01	< 0.01
1950–1959	234	2	236	0.1	3.03	< 0.01
1960–1969	182	2	184	0.13	3.87	< 0.01
1970–1979	118	32	150	15.07	28.76	< 0.01
1980–1989	66	35	101	25.46	44.77	< 0.01
1990–1999	84	32	116	19.69	36.65	< 0.01
2000–2009	114	27	141	13.01	26.62	< 0.01