Ios SWIFT图表轴订购问题

它将一个人的睡眠分为4个类别:清醒、快速、核心和深度.我得到了我想要的图表，显示了晚上不同时间(每小时)的睡眠数据，但我不知道如何让我的Y轴以正确的顺序显示.我希望它被分成四个阶段，每个睡眠阶段，从最高清醒开始，在REM以下，在核心以下，在底部深度，图形高度的25%.然而，无论我try 什么，它都保持着秩序的核心，清醒，深沉，快速.我试过使用.chartYAxis，但它似乎没有任何作用.我可以在文档中看到如何针对数字或日期调整它，但对于我想要的，我非常困惑，特别是当我没有收到错误时，它只是无法默默地对它们进行排序.我想过以某种方式使用Integer来表示每种睡眠类型，0=唤醒，4=深度，并以某种方式将它们对应到字符串值，但我不确定如何实现这一点.谢谢你的帮助！

enum SleepType: String, Plottable, CaseIterable {
    case Awake
    case REM
    case Core
    case Deep
}

struct SingleSleep: Hashable, Identifiable {
    let id = UUID()
    let startDate: Date
    let stopDate: Date
    var sleepTime: TimeInterval = 0 //in minutes
    var sleepType: SleepType
}

struct SleepExampleView: View {
    
    var sleep = [
        SingleSleep(startDate: Date(timeIntervalSinceReferenceDate: 729208384), stopDate: Date(timeIntervalSinceReferenceDate: 729209374), sleepTime: 16.5, sleepType: .Core),
        SingleSleep(startDate: Date(timeIntervalSinceReferenceDate: 729209374), stopDate: Date(timeIntervalSinceReferenceDate: 729209404), sleepTime: 16.5, sleepType: .Awake),
        SingleSleep(startDate: Date(timeIntervalSinceReferenceDate: 729209404), stopDate: Date(timeIntervalSinceReferenceDate: 729209794), sleepTime: 16.5, sleepType: .Core),
        SingleSleep(startDate: Date(timeIntervalSinceReferenceDate: 729209794), stopDate: Date(timeIntervalSinceReferenceDate: 729211234), sleepTime: 16.5, sleepType: .Deep),
        SingleSleep(startDate: Date(timeIntervalSinceReferenceDate: 729211234), stopDate: Date(timeIntervalSinceReferenceDate: 729211864), sleepTime: 16.5, sleepType: .REM),
    ]
    
    var body: some View {
        //chart
        
        Chart {
            ForEach(sleep, id: \.self) { sleep in
                LineMark(
                    x: .value("Time", sleep.startDate),
                    y: .value("Type", sleep.sleepType.rawValue)
                )
            }
        }
        .chartYAxis {
            AxisMarks(
                values: [SleepType.Awake.rawValue, SleepType.REM.rawValue, SleepType.Core.rawValue, SleepType.Deep.rawValue]
              )
        }
        .chartXAxis {
            AxisMarks(values: .stride(by: .hour, count: 1)) { value in
                AxisValueLabel(format: .dateTime.hour(), centered: true)
            }
        }
        .frame(width: 300, height: 300)
        .preferredColorScheme(.dark)
        .background(.clear)
    }
}