I have a dataframe like below:

```
text <- "
brand   a   b   c   d   e   f
nissan  99.21   99.78   6496    1.28    216 0.63
toyota  99.03   99.78   7652    1.39    205 0.60
"
df <- read.table(textConnection(text), sep="\t", header = T)

```

I'm trying to get all the variables for the two groups plotted in a single ggplot using `face_wrap`as below:

```
library(reshape2)
library(ggplot2)
library(ggthemes)
library(RColorBrewer)
ggplot(melt(df, id = "brand")) + 
  aes(brand, value, fill = brand) + 
  geom_bar(stat = "identity", position='dodge') +
  geom_text(data=melt(df, id = "brand"), angle = 0, 
               aes(brand, value,
                   label = ifelse(value > 100, round(value, 0), value) ) ) +
  facet_wrap(~ variable, scales = "free_y") + 
  scale_fill_brewer(palette = "Paired") + 
    theme(
      legend.position = "top",
      strip.text.y = element_text(angle = 0),
      axis.text.x = element_blank(),
      axis.text.y = element_blank(),
      axis.ticks = element_blank()
      )

```

It works well except for one thing. The apparent differences between the group for value of a variable is not coming out very well visually. For example for variable `a` I want the height of the bars to be such that it is clear which is the higher one in an easier fashion. How do I get the height difference between such close values to be larger? 

[![enter image description here](https://i.stack.imgur.com/mHAyG.jpg)](https://i.stack.imgur.com/mHAyG.jpg)