Change origin for time series in r - r

Question

I have a time series in R that I would like to work with, spanning from 01-01-52 to 01-01-88. (1952 to 1988). 37 observations.
However, when I read it in in R, I encounter the problem that the observations from 01-01-52 to 01-01-68 are interpreted as being in 2052 etc., rather than 1952.
How do I force R to read in all the data as being from 1952 to 1988?
Link to my data: https://www.dropbox.com/s/93foyc238skt3xj/AgricIndus.csv?dl=0
This is the code I have used. Do you know what I need to do with my code to make it read properly?
agri <- read.table("AgricIndus.csv",
sep = ",", header = TRUE, skip = 0,
stringsAsFactors = FALSE)
agri$time <- as.Date(agri$time, "%m-%d-%y")
agri.xts <- xts(agri[, 2:3], order.by = agri$time)

Answer 1

One way (hack) can be the following:
agri$time <- as.Date(paste0(substring(agri$time,1,6), '19', substring(agri$time,7,8)),
"%m-%d-%Y")
agri$time
# [1] "01-01-52" "01-01-53" "01-01-54" "01-01-55" "01-01-56" "01-01-57" "01-01-58" "01-01-59" "01-01-60" "01-01-61" "01-01-62" "01-01-63" "01-01-64" "01-01-65"
# [15] "01-01-66" "01-01-67" "01-01-68" "01-01-69" "01-01-70" "01-01-71" "01-01-72" "01-01-73" "01-01-74" "01-01-75" "01-01-76" "01-01-77" "01-01-78" "01-01-79"
# [29] "01-01-80" "01-01-81" "01-01-82" "01-01-83" "01-01-84" "01-01-85" "01-01-86" "01-01-87" "01-01-88"

Answer 2

If you can be sure that your time series is regular then the it is probably the easiest to generate a regular date sequence like so:
agri$time <- seq.Date(as.Date("1952-01-01"),as.Date("1988-01-01"),by='years’)
Another easy solution that would work for irregular time series as well would be to read your data as years 52 to 88 with format = %m-%d-%Y (capitalized “Y” !) and add 1900 years:
df$time <- as.POSIXlt(as.Date(df$time,format = '%m-%d-%Y'))
df$time$year <-df$time$year + 1900
df$time <- as.Date(df$time)
df$time
[1] "1952-01-01" "1953-01-01" "1954-01-01" "1955-01-01"
[5] "1956-01-01" "1957-01-01" "1958-01-01" "1959-01-01"
[9] "1960-01-01" "1961-01-01" "1962-01-01" "1963-01-01"
[13] "1964-01-01" "1965-01-01" "1966-01-01" "1967-01-01"
[17] "1968-01-01" "1969-01-01" "1970-01-01" "1971-01-01"
[21] "1972-01-01" "1973-01-01" "1974-01-01" "1975-01-01"
[25] "1976-01-01" "1977-01-01" "1978-01-01" "1979-01-01"
[29] "1980-01-01" "1981-01-01" "1982-01-01" "1983-01-01"
[33] "1984-01-01" "1985-01-01" "1986-01-01" "1987-01-01"
[37] "1988-01-01"