我在研究ggplot代码。我有一个tsible格式的数据集AirPassenger，我想创建一个分面网格图，其中包含四个线图，显示观察到的数据、趋势、季节和不规则的分量。我已经设法使用以下代码创建了绘图：

library(fpp3)
library(tsibble)
library(ggplot2)
library(scales)
library(zoo)

# Load the data
pr1<-AirPassengers

# Convert time series to tsibble format
pr1_tsibble <- as_tsibble(pr1)

# Apply X-13ARIMA-SEATS model and perform decomposition
fit <- pr1_tsibble %>%
  model(X_13ARIMA_SEATS(value ~ transform(`function` = "none") + x11(mode = "add"))) %>%
  components()

# Extract components
index <- pr1_tsibble$index
data <- pr1_tsibble$value
trend <- fit$trend
seasonal <- fit$seasonal
irregular <- fit$irregular

# Combine components with the original data
combined <- data.frame(index, data, trend, seasonal, irregular)

library(dplyr)
combined <- combined %>%
  mutate(year = as.factor(format(index, "%Y")))
combined$index<-as.Date(combined$index, format= "%Y%b")

ggplot(combined, aes(x = index)) +
  geom_line(aes(y = data, color = "Observed")) +
  geom_line(aes(y = trend, color = "Trend"))+
  geom_line(aes(y = seasonal, color = "Seasonal")) +
  geom_line(aes(y = irregular, color = "Irregular"))+
  xlab('') + ylab("") +
  theme_light() +
  scale_color_manual(
    values = c("Observed" = "grey", "Trend" = "black", "Seasonal" = "green", "Irregular" = "blue"),
    name = ""
  ) +
  scale_y_continuous(
    labels = function(x) format(x, nsmall = 2)
  )+
  scale_x_date(labels = NULL, breaks = NULL, 
               date_minor_breaks = "1 month") + 
  facet_wrap(~year, nrow=1, scales= 'free_x',
             strip.position = 'bottom')+
  theme(panel.spacing.x = unit(0, "lines"),
        panel.grid = element_blank(), 
        legend.position = "top",
        strip.background = element_rect(colour = "white", fill = "grey"))

它生成了图：

我在X轴标签中所期望的..

当前的图几乎是我所需要的，但我希望线图跨越刻面网格连接。目前，每个线图在年份之间都是断开的。我如何修改代码以在facet网格上实现连续的geom_line？
任何帮助或建议将不胜感激！