J Neurol (2011) 258:1140–1149 1143 there was a net gain of 150,000 immigrants from high MS risk countries, 90% from UKI, and 90% of the total had entered Australia in 1911–1932. Massive increases then ensued, with 30,000 new entrants each year 1947–1953, two-thirds from the ‘‘other’’ countries; almost half these immigrants settled in NSW. The next period of 1954–1960 saw almost 20,000 more annually, half to NSW and the majority still from the ‘‘other’’ lands. The 1961–1970 period brought an additional 28,000 each year, but this time 84% were from UKI and only about one-third of the total went to NSW. In the last period of 1971–1981, 14,000 a year arrived, predominantly from the other countries, and this time with few entrants to NSW and most to SA. In this 35 year postwar period, there were then a total of 770,000 new residents from high risk MS countries or an average of 22,000 each year, with overall only a modest excess of UKI (54%) over the other immigrant group. Prevalence in 1981 Prevalence rates by age for MS among the UKI immigrants in each of the four states and their total are given in Fig. 2 Average annual number of new immigrants born in MS high risk countries who entered Australia between each census. Numbers (1,0009) indicated by hatched columns for UKI and by open columns above the UKI for the other high risk countries. Data in Table 1 Table 2 MS crude prevalence rates per 100,000 population by age and state for Four States of Australia, with age-adjusted (US1960) rates; UKI immigrants 1981 Age 0–9 10–9 20–9 30–9 40–9 50–9 60–9 70? Total Age adjusted rate Age 0–9 10–9 20–9 30–9 40–9 50–9 60–9 70? Total Age adjusted rate NSW Pop 12,586 27,221 47,203 68,154 50,189 45,961 39,810 46,391 337,515 N 0 1 17 50 40 16 15 2 141 Western Australia Pop 10,397 22,526 28,357 37,223 29,714 21,868 18,589 18,768 187,442 Rate – 3.67 36.01 73.36 79.70 34.81 37.68 4.31 41.78 31.52 N 0 1 2 15 21 10 12 5 66 Queensland Pop 5,741 12,042 18,887 28,043 22,130 19,719 18,450 22,091 147,103 Rate – 4.44 7.05 40.30 70.67 45.73 64.55 26.64 35.21 26.90 N 0 0 2 14 10 13 6 6 51 Rate – – 10.59 49.92 45.19 65.93 32.52 27.16 34.67 24.37 Four states Pop 34,834 79,248 121,233 160,987 127,008 109,506 91,923 99,455 824,194 South Australia Pop 6,110 17,459 26,786 27,567 24,975 21,958 15,074 12,205 152,134 N 0 0 3 7 19 8 6 1 44 N 0 2 24 86 90 47 39 14 302 Rate – – 11.20 25.39 76.08 36.43 39.80 8.19 28.92 21.45 Rate – 2.52 19.80 55.28 74.80 47.49 47.87 16.09 36.64 29.00 123