年份	实际留学生数(万人)	GM (1, 1)模型
年份	实际留学生数(万人)	拟合值(万人)	残差	相对残差
2005	11.8515	11.8515	0	0
2006	13.4	17.65928	−4.259277	0.3178565
2007	14.4	19.83468	−5.43468	0.3774084
2008	17.98	22.27807	−4.298066	0.239047
2009	22.93	25.02245	−2.092446	0.09125365
2010	28.47	28.1049	0.3651002	0.01282403
2011	33.97	31.56707	2.402927	0.07073673
2012	39.96	35.45574	4.504256	0.1127191
2013	41.39	39.82345	1.56655	0.03784853
2014	45.98	44.7292	1.250798	0.02720308
2015	52.37	50.23928	2.130717	0.04068583
2016	54.45	56.42814	−1.978137	0.03632942
2017	60.84	63.37938	−2.53938	0.04173866
2018	66.21	71.18693	−4.97693	0.07516886