ggplot2重叠传奇问题

Question

我的传奇重叠有问题。见附图： [在此输入图像说明] [1]

这是我的代码：

#Deer Piezo D01

library(ggplot2)

ggplot() +
  theme_bw() +
  geom_point(data = D01_2016, 
             aes(x = Unit, y = Manual_Depth, colour = "2016 WY Manual"), 
             pch = 16, cex = 3, stat = "identity") +
  geom_point(data = D01_2017, 
             aes(x = Unit, y = Manual_Depth, colour = "2017 WY Manual"), 
             pch = 17, cex = 3, stat = "identity") +
  geom_point(data = D01_2018, 
             aes(x = Unit, y = Manual_Depth, colour = "2018 WY Manual"), 
             pch = 18, cex = 3, stat = "identity") +
  geom_line(data = D01, 
            aes(x = Unit, y = H20_Depth_From_Ground, colour= "2017 WY Logger"), 
            cex = 1.10, stat = "identity") +
  ggtitle("D01") +
  labs(x = "Month", y = "Depth to H20 (ft)") + 
  scale_x_continuous(breaks = c(1, 2977, 5857, 8833, 11809, 14497, 17473, 20353, 23329,
                                26209, 29185, 32161),
                     labels = c("October", "November", "December", "January",
                                "February", "March", "April", "May",
                                "June", "July", "August", "September")) +
  theme(panel.grid.minor.x = element_blank(), 
        panel.grid.major.x = element_blank()) +
  theme(plot.title = element_text(hjust = 0.5)) +
  theme(legend.background = element_rect(color = "black",
                                         fill = "grey90", 
                                         size = 1, 
                                         linetype = "solid"), 
        plot.title = element_text(hjust = 0.5), 
        legend.title = element_blank()) +
  scale_shape_identity()