ah sorry, the endpoint does not provide "hire rate" attribute, but please check buyer attribute :

hire rate is calculated using this formula : totalJobsWithHires / postedCount * 100

eg. in JavaScript:

hireRate() {
    const t = this.buyer.stats.totalJobsWithHires / this.postedCount * 100;
    return Math.min(Math.ceil(t), 100) || 0
}

Buyer :

"buyer": {
    "avgHourlyJobsRate": {
        "amount": 27.29022302174609
    },
    "company": {
        "companyId": "776126522584219648",
        "contractDate": "2016-09-14T00:00:00.000Z",
        "profile": {
            "industry": "Sales & Marketing",
            "size": 10
        }
    },
    "jobs": {
        "openCount": 1,
        "postedCount": 124 <===== [postedCount]
    },
    "location": {
        "city": "Salt Lake City",
        "country": "United States",
        "countryTimezone": "America/Sao_Paulo (UTC-03:00)",
        "offsetFromUtcMillis": -10800000
    },
    "stats": {
        "activeAssignmentsCount": 14,
        "feedbackCount": 79,
        "hoursCount": 23341.67,
        "score": 4.92,
        "totalAssignments": 126,
        "totalCharges": {
            "amount": 701153.25
        },
        "totalJobsWithHires": 92 <===== [totalJobsWithHires]
    }
}