Table 4 Percentages of the genotypic (n) and the mutant [119S] allelic (95% confidence interval) frequencies of the ace-1 gene in Anopheles gambiae s.l. populations by period and species using a layered 2 × 3 × 3 contingency table

Ag

BIRS

80

0% (0)

4% (3)^a

96% (77)^a

2% (0–4%)

DIRS

90

4% (4)

33% (30)^b

62% (56)^b

21% (15–27%)

WIRS

833

0% (0)

7% (57)^a

93% (776)^a

3% (3–4%)

Non-Ag

BIRS

1

0% (0)

0% (0)

100% (1)^a

0% (0–0%)

DIRS

10

0% (0)

20% (2)^a

80% (8)^a

10% (−3% to –23%)

WIRS

78

0% (0)

4% (3)^a

96% (75)^a

2% (0–4%)

Total

BIRS

81

0% (0)

4% (3)^a

96% (78)^a

2% (0–4%)

DIRS

100

4% (4)

32% (32)^b

64% (64)^b

20% (14–26%)

WIRS

911

0% (0)

7% (60)^a

93% (851)^a

3% (2–4%)