ydat=c(121.6,119.7,118.2,118.6,118.9,119.6,119.2,120.2,121.0,121.1,122.3,119.9,119.0,119.2,121.1,119.8,120.9,120.0,120.0,120.4,119.3,118.1,119.7,118.0,118.4,120.2,121.4,120.9,120.8,121.1,122.1,120.4,118.8,119.4,118.4,119.5,120.1,120.1,120.9,120.3,120.7,119.7,120.1,119.3,118.9,121.6,121.0,119.2,118.4,119.9,120.8,118.9,119.3,120.0,120.4,120.8,120.8,119.8,120.2,117.7,116.4,116.0,116.5,117.3,119.2,119.2,121.5,122.1,121.2,121.2,120.2,119.9,121.7,119.1,119.8,120.9,119.4,119.9,120.1,118.8,117.6,118.8,119.6,120.0,118.4,119.7,119.6,119.9,119.5,118.0,118.2,118.0,118.0,117.5,118.4,119.2,119.6,119.0,120.1,120.4)