I found a code on the web that must (will) produce a graphics representing some data from the U.S. Department of Labor: Bureau of Labor Statistics.:

```
library(ggplot2)
df <- as.data.frame(read.csv("unemp.csv", colClasses = c("Date", "numeric")))
p <- ggplot(df,aes(x=date,y=ratio))
p + geom_point() + geom_smooth() + xlab("Year") + 
ylab("Civilian Employment Population Ratio (%)") + 
labs(title="Bureau of Labor Statistics Series EMRATIO 
            (seasonally adjusted) to 2012-10-01")

```

but it do not working and produces this error:

```
Don't know how to automatically pick scale for object of type function. Defaulting to continuous
Error in eval(expr, envir, enclos) : object 'ratio' not found

```

What is missing in this code?

'unemp.csv' contain data from [here](http://research.stlouisfed.org/fred2/data/EMRATIO.txt) and resulting graphics must looking like [this](http://qph.is.quoracdn.net/main-qimg-138609a199fdeae521241db869a38850).