| | 2009 | | | Rank | Provinces | Out-patients | | 1 | Nakhon Ratchasima | 6,813,115 | | 2 | Chiang Mai | 4,696,742 | | 3 | Khon Kaen | 4,376,697 | | 4 | Chiang Rai | 4,071,494 | | 5 | Nakhon Si Thammarat | 3,672,848 | | 6 | Udon Thani | 3,626,623 | | 7 | Nakhon Pathom | 3,546,648 | | 8 | Surin | 3,536,103 | | 9 | Roi Et | 3,522,953 | | 10 | Si Sa Ket | 3,401,956 | | | Whole Kingdom | 152,428,645 |
| | | 2010 | | | Rank | Provinces | Out-patients | | 1 | Nakhon Ratchasima | 7,894,690 | | 2 | Chiang Mai | 5,540,693 | | 3 | Khon Kaen | 4,754,358 | | 4 | Nakhon Si Thammarat | 4,243,368 | | 5 | Chiang Rai | 4,179,621 | | 6 | Si Sa Ket | 4,164,776 | | 7 | Udon Thani | 3,864,425 | | 8 | Nakhon Pathom | 3,822,591 | | 9 | Surin | 3,815,408 | | 10 | Tak | 3,340,448 | | | Whole Kingdom | 164,766,694 |
| | | 2011 | | | Rank | Provinces | Out-patients | | 1 | Nakhon Ratchasima | 8,174,274 | | 2 | Chiang Mai | 5,975,960 | | 3 | Khon Kaen | 4,509,141 | | 4 | Buri Ram | 4,197,859 | | 5 | Nakhon Si Thammarat | 3,987,512 | | 6 | Chaiyaphum | 3,937,890 | | 7 | Chiang Rai | 3,832,294 | | 8 | Si Sa Ket | 3,692,603 | | 9 | Udon Thani | 3,665,895 | | 10 | Nakhon Pathom | 3,563,580 | | | Whole Kingdom | 170,790,297 |
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