i: the kind of industry;j: the year;: the change rate;Wi: major industrial eco-nomic indices, including investment, value, and employment;Si: the area of the enterprise;
Yi: the added value of industry;Pi: the output of industrial produc-tion;Pi
: the degree of gray incidence;Qi: the output of industry in Beijing;Zi:the per capita income in Beijing;Ti: the wage of industrial employees;Xi: the number of employees in this sector;Ki: the number of technological employees;Li: the volume of water use;
Ni: the quantity of water run-off, including sewage,exhaust gas, and solid-rejectamenta.