Put xtable and ggplot2 output side-by-side in Beamer

MWE:

\documentclass[pdf, t, 10pt]{beamer}
\usetheme{Antibes}
\mode<presentation>{}
\usepackage{array}
\newcolumntype{R}[1]{>{\raggedleft\arraybackslash\hspace{0pt}}p{#1}}

\begin{document}
\begin{frame}[fragile]
<<echo=FALSE, fig.show='hold', results='asis', fig.width=3, fig.height=3, fig.align='right'>>=
# Ficticious data
grad <- c(0.846, 0.863, 0.852, 0.873)
counts <- c(500, 485, 520, 545)
year <- c(1, 2, 3, 4)
library(ggplot2)
library(xtable)

format_pct <- function(x){
  paste0(round(x * 100, 1), "%")
}
df <- data.frame(Year = as.integer(year),
                 Counts = as.integer(counts),
                 Grad_Rate = grad,
                 stringsAsFactors = FALSE)
p <- ggplot(df, aes(x = Year, y = Grad_Rate, weight = counts)) + 
  geom_point() +
  geom_smooth(method = "lm") + 
  theme_bw() + 
  scale_y_continuous(labels = format_pct, breaks = seq(0.5, 1, by = 0.05),
                     limits = c(0.8, 1)) + 
  xlab("Year") + 
  ylab("Graduation Rate")
print(xtable(df, align = c("l", "R{0.05\\textwidth}", "R{0.15\\textwidth}", "R{0.12\\textwidth}")), 
      include.rownames = FALSE,
      latex.environments="flushleft"
      )
p
@
\end{frame}

\end{document}

Output:

Desired output:

I would like to get rid of that extra line that (for some strange reason) is appearing in the columns of the xtable, and would like to place the xtable and the ggplot2 output side-by-side. It is fine if the widths have to be adjusted.