An Exponential Curve Model and Its Application in Forecasting Private Car Ownership of China

Table 1

Calculation results of private car ownership data by exponential curve, modified exponential curve, and the new exponential curve of first order polynomial term.

Year	Actual value	Exponential curve	APE (%)	Modified exponential curve	APE (%)	New exponential curve	APE (%)
2003	1219.23	1353.2936	10.9958	1151.4744	5.5572	1371.5434	12.4926
2004	1481.66	1659.5926	12.0090	1480.2007	0.0985	1451.6567	2.0250
2005	1848.07	2035.2180	10.1267	1880.9844	1.7810	1725.7599	6.6183
2006	2333.32	2495.8609	6.9661	2369.6205	1.5557	2190.4378	6.1236
2007	2876.22	3060.7638	6.4162	2965.3666	3.0994	2842.3354	1.1781
2008	3501.39	3753.5246	7.2010	3691.7013	5.4353	3678.1568	5.0485
2009	4574.91	4603.0820	0.6158	4577.2499	0.0511	4694.6642	2.6176
2010	5938.71	5644.9248	4.9470	5656.9122	4.7451	5888.6766	0.8425
2011	7326.79	6922.5741	5.5170	6973.2385	4.8255	7257.0692	0.9516
2012	8838.60	8489.4012	3.9508	8578.1058	2.9472	8796.7721	0.4732
2013	10501.68	10410.8576	0.8648	10534.7629	0.3150	10504.7694	0.0294
2014	12339.36	12767.2086	3.4673	12920.3228	4.7082	12378.0985	0.3139
2015	14099.10	15656.8864	11.0488	15828.8015	12.2682	14413.8487	2.2324
2016	16330.20	19200.6021	17.5773	19374.8241	18.6441	16609.1607	1.7083
2017	18515.10	23546.3879	27.1740	23698.1410	27.9936	18961.2255	2.4095
2018	20574.93	28875.7812	40.3445	28969.1368	40.7982	21467.2836	4.3371
2019		35411.4076		35395.5441		24124.6239
2020		43426.2809		43230.6314		26930.5833
MAPEsimu(%)		5.6438		2.6875		2.3838
MAPEfit(%)		24.0361		24.9260		2.6718
MAPEtotal(%)		10.5484		8.6178		2.4606