since the 1950s" and that women in 2004 were taller and had bigger busts and hips than those of the 1950s. Note however that a 2021 study found that slight changes in measurement placement definition can recategorise up to 40% of women into different body shapes, meaning cross-research comparisons may be flawed unless the exact measurement definitions are used. Several similar classifications of women's body shape exist. These include: Sheldon: "Somatotype: {Plumper: Endomorph, Muscular: Mesomorph, Slender: Ectomorph}", 1940s Douty's "Body Build Scale: {1,2,3,4,5}", 1968 Bonnie August's "Body I.D. Scale: {A,X,H,V,W,Y,T,O,b,d,i,r}", 1981 Simmons, Istook, & Devarajan "Female Figure Identification Technique (FFIT): {Hourglass, Bottom Hourglass, Top Hourglass, Spoon, Rectangle, Diamond, Oval, Triangle, Inverted Triangle}", 2002 Connell's "Body Shape Assessment Scale: {Hourglass, Pear, Rectangle, Inverted Triangle}", 2006 Rasband: {Ideal, Triangular, Inverted Triangular, Rectangular, Hourglass, Diamond, Tubular, Rounded}, 2006 Lee JY, Istook CL, Nam YJ, "Comparison of body shape between USA and Korean women: {Hourglass, Bottom Hourglass, Top Hourglass, Spoon, Triangle, Inverted Triangle, Rectangle}", 2007. FFIT for Apparel measurements The "Female Figure Identification Technique for Apparel" uses the following formula to identify an individual's body type: Hourglass If (bust − hips) ≤ AND (hips − bust) < AND ((bust − waist) ≥ OR (hips − waist) ≥ ) Bottom hourglass If (hips − bust) ≥ AND (hips − bust) < AND (hips − waist) ≥ AND (high hip/waist) < 1.193 Top hourglass If (bust − hips) > AND (bust − hips) < AND (bust − waist) ≥ Spoon If (hips − bust) > AND (hips − waist) ≥ AND (high hip/waist) ≥ 1.193 Triangle If (hips − bust) ≥ AND (hips − waist) < Inverted triangle If (bust − hips) ≥ AND (bust − waist) < Rectangle If (hips − bust) < AND (bust − hips) < AND (bust − waist) < AND (hips − waist) < Clothing standards Some clothing size standards define categories. Inverted triangle-rectangular categories The Chinese clothing size standards give codes to clothing designed for different ratios between chest and waist. They adapt for a linear scale between inverted triangle/hourglass and rectangular. Rectangular-spoon categories The Japanese and South Korean clothing size standards give codes to women's clothing designed for different ratios between hips and chest. The German standards similarly use hip and bust measures. They all adapt for a linear scale between rectangular and spoon shapes. The German sizing system also has height categories for short, regular and tall women,