Year	Advert. Expenditure	Sales	Growth rate of Ad. Expenditure	Growth rate of Sales
	(x, 000)	(y, 000)
2010	19	84
2011	22	108	18%	29%
2012	32	82	46%	-24%
2013	42	86	32%	6%
2014	47	84	11%	-3%
2015	46	94	-2%	11%
2016	58	103	27%	10%
2017	63	115	8%	12%
2018	70	106	11%	-8%
2019	80	142	15%	34%
Total	478	1003

1. How much is the average of growth rate of Ad. Expenditure and growth rate of sales, respectively? Show your workings and explain your choice of mean used.