Find average of chosen courses over given semesters, as well as calculate the average of the given semesters over the chosen courses

FindCourseAndSemesterAvg.kt

import java.net.URL

data class Course(val number: String, var avg: Double = 0.0, val avgBySem: MutableMap<String, Double> = mutableMapOf())
val bucket = listOf("104031", "104166", "234114", "234129",
    "104032", "104134", "114071", "234124", "234141",
    "044252", "094412", "234218", "234292", "236319")

val semesters = listOf("202001", "201902", "201901", "201802", "201801", "201702", "201701", "201602", "201601")

fun link(course: String, semester: String)
        = "https://raw.githubusercontent.com/michael-maltsev/technion-histograms/master/$course/$semester/Finals.json"

fun main(args: Array<String>) {
    val courses = bucket.map { Course(it) }
    for (course in courses) {
        semesters@for (semester in semesters) {
            val link = link(course.number, semester)
            try {
                val json = URL(link).readText()
                val averageLine = json.split("\n").first { "average" in it }.trim() // bad
                val average = averageLine.split(" ")[1].removePrefix("\"").removeSuffix("\",")
                course.avgBySem[semester] = average.toDouble()
                course.avg = course.avgBySem.values.average()
            } catch (e: Exception) {
                continue@semesters
            }
        }
    }
    println("--------------")
    println("Course Averages:")
    println("--------------")
    for(course in courses) println("${course.number}: ${course.avg}")
    println("--------------")
    println("Semester Averages:")
    println("--------------")
    for(semester in semesters) {
        var sum = 0.0
        var num = 0
        courses@for(course in courses) {
            if(semester !in course.avgBySem) continue@courses
            num++
            sum += course.avgBySem[semester]!!
        }
        println("$semester: ${sum / num} ($num)")
    }
}