How to get total CPU Idle Time in Objective C/C on OS X?

I need to get total CPU Idle Time in Objective C/C on OS X?

If possible please provide code example which do that. Here is a code I use to get these metrics. As result percentage is not the same I have in Activity Monitor. So I assume CPU time calculation is incorrect:

#include <sys/sysctl.h>
#include <sys/types.h>
#include <mach/mach.h>
#include <mach/processor_info.h>
#include <mach/mach_host.h>

- (void)printCPUUsage
{
    processor_cpu_load_info_t cpuLoad;
    mach_msg_type_number_t processorMsgCount;
    natural_t processorCount;

    uint64_t totalSystemTime = 0, totalUserTime = 0, totalIdleTime = 0, totalCPUTime = 0;

    kern_return_t err = host_processor_info(mach_host_self(), PROCESSOR_CPU_LOAD_INFO, &processorCount, (processor_info_array_t *)&cpuLoad, &processorMsgCount);

    for (natural_t i = 0; i < processorCount; i++) {

        // Calc load types and totals, with guards against 32-bit overflow
        // (values are natural_t)
        uint64_t system = 0, user = 0, idle = 0, total = 0;

        system = cpuLoad[i].cpu_ticks[CPU_STATE_SYSTEM];
        user = cpuLoad[i].cpu_ticks[CPU_STATE_USER];
        idle = cpuLoad[i].cpu_ticks[CPU_STATE_IDLE];

        total = system + user + idle;

        if (total < 1) {
            total = 1;
        }

        totalCPUTime += total;
        totalSystemTime += system;
        totalUserTime += user;
        totalIdleTime += idle;
    }


    double onePercent = totalCPUTime/100.0f;

    NSLog(@"system: %f", (double)totalSystemTime/(double)onePercent);
    NSLog(@"user: %f", (double)totalUserTime/(double)onePercent);
    NSLog(@"idle: %f", (double)totalIdleTime/(double)onePercent);
}