Shifting individual level data to country level data(mean), year on year

Question

I am trying to see the change in variable "A004" on country level, year on year. The data I have is on individual level. Sample Data:

cntry_AN	year	A004
AL	2010	3
AL	2010	4
AL	2011	2
AL	2012	3
DZ	2010	3
DZ	2011	2
DZ	2011	3

I want the output to look like(replaced with means):

cntry_AN	2010	2011	2012
AL	3.5	2	3
DZ	3	2.5	-

Here's the code I am trying:

country_year_summary <- file1 %>% 
  group_by(cntry_AN,year) %>% 
  select(A004) %>% 
  dplyr::summarize(averaged.M = mean(A004))