In the history of Western fashion, the ordinary public clothes of upper- and middle-class women varied only between floor-length and slightly above ankle-length for many centuries before World War I. Skirts of lower-calf or mid-calf length were associated with the practical working garments of lower-class or pioneer women, while even shorter skirt lengths were seen only in certain specialized and restricted contexts (e.g. sea-bathing costumes, or outfits worn by ballerinas on stage). It was not until the mid-1910s that hemlines began to rise significantly (with many variations in height thereafter). Skirts rose all the way from floor-length to near knee-length in only about fifteen years (from late in the decade of the 1900's to the mid-1920's). From WW1 to roughly 1970, a woman had to wear skirts near their currently-fashionable length or be considered almost hopelessly unstylish, but since the 1970's, women's options have widened, and there is no longer really only one single fashionable skirt-length at a time.