Less
than 2%
2%
to 5%
5%
to 10%
10%
to 20%
20%
or above
1977
18
20
42
57
106
1980
24
53
51
62
53
1985
20
38
47
57
81
1990
29
43
49
52
70
1995
14
19
43
77
90
2000
28
31
47
76
61
2005 February
32
33
75
62
41
2005 October
34
61
54
65
29
2010
23
33
59
90
38
2015
16
39
66
83
39
2020
40
38
63
74
28