"airmiles" <-
structure(c(412, 480, 683, 1052, 1385, 1418, 1634, 2178, 3362, 5948, 6109, 
5981, 6753, 8003, 10566, 12528, 14760, 16769, 19819, 22362, 25340, 25343, 
29269, 30514), .Tsp = c(1937, 1960, 1), class = "ts")