year是年份，roe是因变量，其余是自变量

year	ROE	DTA	SIZ	AI
1	14.76	0.35	231766077.88	2.55
2	15.34	0.35	255900334.01	3.11
3	12.11	0.31	289669860.95	2.57
4	13.38	0.36	320385094.01	3.59
1	1.63	0.38	954582910.91	1.04
2	2.53	0.41	1112773604.44	0.85
3	3.62	0.43	1276037701.94	0.78
4	4.14	0.50	1503278715.63	0.73
1	2.40	0.21	1886978951.19	1.42
2	2.03	0.30	2096963709.91	1.07
3	6.83	0.34	2321927213.25	1.22
4	5.81	0.37	2614233634.62	1.05
1	44.14	0.43	3109373717.78	2.09
2	51.46	0.37	4068901991.90	1.97
3	40.84	0.68	4560115455.25	1.42
4	32.93	0.63	4951627463.77	1.51
1	17.11	0.46	1394118761.31	0.74
2	19.68	0.39	1516792783.12	0.70
3	22.64	0.41	1328680422.56	0.84
4	23.90	0.44	1816438510.25	0.76
1	19.75	0.30	351137848.46	2.73
2	22.09	0.04	475162798.40	6.02
3	43.29	0.06	1220493429.97	2.05
4	32.09	0.05	1261620656.52	2.72