It's centered, but your code is struggling to hold the page together.
Result: 0 errors / 83 warnings
line 39 column 1 - Warning: inserting implicit <p>
line 42 column 4 - Warning: missing </strong> before </center>
line 46 column 1 - Warning: inserting implicit <strong>
line 46 column 1 - Warning: missing </strong> before <p>
line 46 column 4 - Warning: inserting implicit <strong>
line 45 column 1 - Warning: missing </center>
line 37 column 1 - Warning: missing </center>
line 55 column 44 - Warning: discarding unexpected </center>
line 31 column 1 - Warning: missing </div> before <tr>
line 56 column 3 - Warning: inserting implicit <table>
line 57 column 1 - Warning: <br> isn't allowed in <tr> elements
line 56 column 3 - Info: <tr> previously mentioned
line 57 column 5 - Warning: <br> isn't allowed in <tr> elements
line 56 column 3 - Info: <tr> previously mentioned
line 59 column 1 - Warning: <p> isn't allowed in <tr> elements
line 56 column 3 - Info: <tr> previously mentioned
line 60 column 1 - Warning: <center> isn't allowed in <tr> elements
line 56 column 3 - Info: <tr> previously mentioned
line 60 column 1 - Warning: missing </center> before <td>
line 64 column 28 - Warning: unescaped & which should be written as &
line 64 column 66 - Warning: replacing </p> by <br>
line 64 column 77 - Warning: discarding unexpected </a>
line 64 column 86 - Warning: discarding unexpected </center>
line 67 column 1 - Warning: <p> isn't allowed in <tr> elements
line 56 column 3 - Info: <tr> previously mentioned
line 68 column 1 - Warning: <center> isn't allowed in <tr> elements
line 56 column 3 - Info: <tr> previously mentioned
line 124 column 1 - Warning: discarding unexpected </center>
line 128 column 7 - Warning: inserting implicit <p>
line 140 column 21 - Warning: discarding unexpected </strong>
line 140 column 30 - Warning: discarding unexpected </font>
line 138 column 1 - Warning: missing </strong> before </td>
line 137 column 1 - Warning: missing </font> before </td>
line 142 column 1 - Warning: discarding unexpected </center>
line 153 column 26 - Warning: replacing unexpected font by </font>
line 158 column 72 - Warning: unescaped & or unknown entity "&path"
line 158 column 78 - Warning: unescaped & or unknown entity "&nats"
line 160 column 4 - Warning: missing </font> before </a>
line 159 column 19 - Warning: missing </font> before </a>
line 159 column 4 - Warning: missing </font> before </a>
line 151 column 37 - Warning: missing </font> before </p>
line 151 column 1 - Warning: missing </span> before </p>
line 150 column 1 - Warning: missing </b> before </p>
line 163 column 1 - Warning: inserting implicit <b>
line 163 column 1 - Warning: inserting implicit <span>
line 164 column 1 - Warning: missing </span> before <center>
line 163 column 1 - Warning: missing </b> before <center>
line 163 column 1 - Warning: missing </span> before <center>
line 163 column 1 - Warning: missing </b> before <center>
line 166 column 1 - Warning: inserting implicit <b>
line 166 column 1 - Warning: inserting implicit <span>
line 167 column 1 - Warning: missing </b> before </a>
line 166 column 41 - Warning: missing </font> before </a>
line 166 column 1 - Warning: replacing unexpected font by </font>
line 168 column 1 - Warning: discarding unexpected </span>
line 168 column 8 - Warning: discarding unexpected </a>
line 168 column 12 - Warning: discarding unexpected </b>
line 168 column 16 - Warning: discarding unexpected </blink>
line 171 column 12 - Warning: discarding unexpected </table>
line 172 column 1 - Warning: discarding unexpected </div>
line 130 column 1 - Warning: missing </center>
line 20 column 1 - Warning: <style> inserting "type" attribute
line 28 column 1 - Warning: <body> proprietary attribute "topmargin"
line 74 column 1 - Warning: <img> proprietary attribute "nosave"
line 77 column 1 - Warning: <img> proprietary attribute "nosave"
line 81 column 1 - Warning: <img> proprietary attribute "nosave"
line 85 column 1 - Warning: <img> proprietary attribute "nosave"
line 91 column 1 - Warning: <img> proprietary attribute "nosave"
line 95 column 1 - Warning: <img> proprietary attribute "nosave"
line 99 column 1 - Warning: <img> proprietary attribute "nosave"
line 103 column 1 - Warning: <img> proprietary attribute "nosave"
line 110 column 1 - Warning: <img> proprietary attribute "nosave"
line 115 column 1 - Warning: <img> proprietary attribute "nosave"
line 119 column 1 - Warning: <img> proprietary attribute "nosave"
line 123 column 1 - Warning: <img> proprietary attribute "nosave"
line 134 column 1 - Warning: <a> attribute "href" lacks value
line 139 column 1 - Warning: <a> attribute "href" lacks value
line 146 column 1 - Warning: <table> proprietary attribute "bordercolor"
line 36 column 1 - Warning: trimming empty <p>
line 39 column 1 - Warning: trimming empty <p>
line 46 column 1 - Warning: trimming empty <strong>
line 59 column 1 - Warning: trimming empty <p>
line 60 column 1 - Warning: trimming empty <center>
line 67 column 1 - Warning: trimming empty <p>
line 128 column 7 - Warning: trimming empty <p>
line 164 column 1 - Warning: trimming empty <span>
line 163 column 1 - Warning: trimming empty <b>
line 163 column 1 - Warning: trimming empty <span>
line 163 column 1 - Warning: trimming empty <b>