одна категория баров меньше остальных и не выровнена по оси

Question

Выше доминирования столбцы меньше и не совпадают с меткой оси.

x<- ggplot(avg, aes(x=avg$`NewData$treatment`, y=avg$sc, fill=as.factor(avg$`NewData$gender`)))+
  geom_bar(position= position_dodge(), stat="identity") +
  ylab(lab="Effort")+
  xlab(lab="Treatment")+
  ggtitle("Effort Treatment and Gender")+
  scale_fill_discrete(name="Gender", breaks=c("1","2"), labels=c("Male","Female"))+
scale_x_discrete(limits=c("matrix_individual","matrix_tournament","matrix_fixed", "matrix_dictator"),
                 labels=c("matrix_individual" = "Piece-Rate", "matrix_tournament"= "Dominance", "matrix_fixed" = "Fixed", "matrix_dictator" = "Influence"))+
  theme(axis.text.x=element_text(size=10))