I have a data panel from 2009 to 2018 where each year (ano) there is an occurrence of the total number of employees (total) for each company (cnpjcei).
ano cnpjcei total
<dbl> <chr> <int>
1 2009 1000786001505 25
2 2010 1000786001505 23
3 2011 1000786001505 10
4 2012 1000786001505 8
5 2013 1000786001505 7
6 2014 1000786001505 9
7 2015 1000786001505 9
8 2016 1000786001505 9
9 2017 1000786001505 8
10 2018 1000786001505 9
11 2009 1001193000168 32
12 2010 1001193000168 41
13 2011 1001193000168 76
14 2012 1001193000168 93
15 2013 1001193000168 67
16 2014 1001193000168 75
17 2015 1001193000168 42
18 2016 1001193000168 91
19 2017 1001193000168 68
20 2018 1001193000168 84
Basically, I want to calculate the average number of employees in the period (2009 to 2018) for each company (cnpjcei)
cnpjcei average
<chr> <int>
1 1000786001505 11.7
2 1001193000168 66.9
Suggestions?