The size range of trousers, T-shirts and shirts worn by northerners. What size ratio should the northern clothing store distribute goods?

Northerners are bigger than southerners. If it is the first time to purchase goods, try to match them according to the size of 1: 2: 2: 1, and there is less demand for small size. But according to the style of brand management, young women's wear and mature women's wear are completely different. Young women's wear has more demand for small and medium size, more demand for large size and less demand for mature women's wear. Then adjust the size ratio in replenishment according to the sales volume of one week or one month.