代码中有点混乱

嗨，我正在阅读一本名为"开始Visual C# 2012编程"的书，在本书的第4章中，在倾斜部分，他们给出了以下示例。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ChapterFourExcerciseFour
{
    class Program
    {
        static void Main(string[] args)
        {
            double balance, interestRate, targetBalance;
            int totalYears = 0;
            //reading balance from the console and saving it into the balance
            Console.WriteLine("Please Enter your balance");
            balance = Convert.ToDouble(Console.ReadLine());
            //reading interesrrate from the console and saving it into tht interesrrate
            Console.WriteLine("What is your current interest rate");
            interestRate = Convert.ToDouble(Console.ReadLine());
            //reading targetbalance from the console and saving it int the targetbalance
            Console.WriteLine("What balancce would you like to have");
            targetBalance = Convert.ToDouble(Console.ReadLine());
            do
            {
                balance *= interestRate;
                ++totalYears;
            }
            while (balance < targetBalance);
            Console.WriteLine("in {0} years{1} you'll have the balance of {2}.",totalYears, totalYears == 1 ? "" : "s", balance);
            Console.ReadKey();
        }
    }
}

现在在排队

Console.WriteLine("in {0} years{1} you'll have the balance of {2}.",totalYears, totalYears == 1 ? "" : "s", balance);

我不明白为什么使用{1}接近年份意味着他们正在访问" "，总计年份，总计年份 == 1 ？ " ： "s" " 这段代码 ， 为什么你访问这段代码，为什么他们不简单地写

Console.WriteLine("in {0} years you'll have the balance of {1}.",totalYears,balance);

但是当我尝试通过上述行编译代码时，编译器给出了错误：

索引（从零开始）必须大于或等于零且小于参数列表的大小。

为什么会这样？谁能解释一下？