Macro function in R - r

Question

I'm new to R coming from SAS. I am trying to repeat this code for a set of datasets called mort_1969, mort_1970,..., mort_n. How can I modify it so I don't have to rerun it each time, replacing the year variable?
mrt <- read_csv("mort1985.csv")
mrt <- mrt %>%
rename(nchs_code = countyrs)
crosswalk <- read_csv("crosswalk.csv")
crosswalk <- crosswalk %>%
select(-X1)
mrt_cw <- left_join(mrt, crosswalk, by = "nchs_code")
mrt_cw1 <- mrt_cw %>%
filter(cityrs == 999) %>%
select(fips, racer3) %>%
mutate(count = 1) %>%
group_by(fips, racer3) %>%
summarise(mrt_c = sum(count)) %>%
mutate(racer3=replace(racer3, racer3==1, "white_pop"),
racer3=replace(racer3, racer3==2, "black_pop"),
racer3=replace(racer3, racer3==3, "other_race_pop"))
mrt_cw2 <- pivot_wider(
data=mrt_cw1,
names_from = racer3,
values_from = mrt_c
)
#Convert NAs to 0 and drop original variables
mrt_cw3 <- mrt_cw2 %>%
mutate(white_m = ifelse(is.na(white_pop), 0, white_pop),
black_m = ifelse(is.na(black_pop), 0, black_pop),
other_race_m = ifelse(is.na(other_race_pop), 0, other_race_pop)) %>%
select(-white_pop, -black_pop, -other_race_pop) %>%
mutate(total_m = white_m + black_m + other_race_m)
pop <- read_csv('population_file.csv')
##########################ADD YEAR
pop <- pop %>%
filter(year == 1985) %>%
select(-X1, -year)
mrt_cw4 <- left_join(mrt_cw3, pop, by = "fips")
mrt_cw5 <- mrt_cw4 %>%
mutate(ttl_rate = (total_m/total_pop)*100,
blk_rate = (black_m/black_pop)*100,
wht_rate = (white_m/white_pop)*100,
otr_rate = (other_race_m/other_races_pop)*100)
mrt_cw6 <- mrt_cw5 %>%
mutate(high_flag = ifelse(ttl_rate >= 100 | blk_rate >= 100 |
wht_rate >= 100 | otr_rate >= 100, 1, 0))
##########################ADD YEAR
#Save file
write.csv(mrt_cw6, "mort_85.csv")