灰色预测，已知部分年的值，用来预测将来年的值。先建立模型，然后得出系数，再校核系数的精度，精度合适则能够用来进行预测未来年值。-Prediction, known portion of the value that is used to predict the future of values. The first model, and then come coefficient, and then check the accuracy of the coefficient, the accur