Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
Lone Pine International
Table title:
Summary
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Year </th><th colspan=1 rowspan=1 > Dates </th><th colspan=1 rowspan=1 > Rounds </th><th colspan=1 rowspan=1 > Field </th><th colspan=1 rowspan=1 > Avg. Elo </th><th colspan=1 rowspan=1 > Top score </th><th colspan=1 rowspan=1 > Winners </th></tr>
<tr> <td colspan=1 rowspan=1 > 1971 </td><td colspan=1 rowspan=1 > March 14–20 </td><td colspan=1 rowspan=1 > 7 </td><td colspan=1 rowspan=1 > 33 </td><td colspan=1 rowspan=1 > 2190 </td><td colspan=1 rowspan=1 > 6 </td><td colspan=1 rowspan=1 > Larry Evans (United States) </td></tr>
<tr> <td colspan=1 rowspan=1 > 1972 </td><td colspan=1 rowspan=1 > March 12–18 </td><td colspan=1 rowspan=1 > 7 </td><td colspan=1 rowspan=1 > 35 </td><td colspan=1 rowspan=1 > 2262 </td><td colspan=1 rowspan=1 > 6 </td><td colspan=1 rowspan=1 > Svetozar Gligorić (Yugoslavia) </td></tr>
<tr> <td colspan=1 rowspan=1 > 1973 </td><td colspan=1 rowspan=1 > March 18–24 </td><td colspan=1 rowspan=1 > 7 </td><td colspan=1 rowspan=1 > 48 </td><td colspan=1 rowspan=1 > 2322 </td><td colspan=1 rowspan=1 > 6 </td><td colspan=1 rowspan=1 > Arthur Bisguier (United States) </td></tr>
<tr> <td colspan=1 rowspan=1 > 1974 </td><td colspan=1 rowspan=1 > March 24–30 </td><td colspan=1 rowspan=1 > 7 </td><td class="highlighted"  colspan=1 rowspan=1 > 53 </td><td class="highlighted"  colspan=1 rowspan=1 > 2310 </td><td colspan=1 rowspan=1 > 6 </td><td colspan=1 rowspan=1 > Walter Browne (United States) </td></tr>
<tr> <td colspan=1 rowspan=1 > 1975 </td><td colspan=1 rowspan=1 > April 13–24 </td><td colspan=1 rowspan=1 > 10 </td><td class="highlighted"  colspan=1 rowspan=1 > 44 </td><td class="highlighted"  colspan=1 rowspan=1 > 2428 </td><td colspan=1 rowspan=1 > 7½ </td><td colspan=1 rowspan=1 > Vladimir Liberzon (Israel) </td></tr>
<tr> <td colspan=1 rowspan=1 > 1976 </td><td colspan=1 rowspan=1 > March 7–13 </td><td colspan=1 rowspan=1 > 7 </td><td colspan=1 rowspan=1 > 57 </td><td colspan=1 rowspan=1 > 2371 </td><td colspan=1 rowspan=1 > 5½ </td><td colspan=1 rowspan=1 > Tigran Petrosian (Soviet Union) </td></tr>
<tr> <td colspan=1 rowspan=1 > 1977 </td><td colspan=1 rowspan=1 > March 20–30 </td><td colspan=1 rowspan=1 > 9 </td><td colspan=1 rowspan=1 > 48 </td><td colspan=1 rowspan=1 > 2410 </td><td colspan=1 rowspan=1 > 6½ </td><td colspan=1 rowspan=1 > Yuri Balashov (Soviet Union) Dragutin Sahović (Yugoslavia) Oscar Panno (Argentina) Nona Gaprindashvili (Soviet Union) </td></tr>
<tr> <td colspan=1 rowspan=1 > 1978 </td><td colspan=1 rowspan=1 > April 1–12 </td><td colspan=1 rowspan=1 > 9 </td><td colspan=1 rowspan=1 > 68 </td><td colspan=1 rowspan=1 > 2431 </td><td colspan=1 rowspan=1 > 7½ </td><td colspan=1 rowspan=1 > Bent Larsen (Denmark) </td></tr>
<tr> <td colspan=1 rowspan=1 > 1979 </td><td colspan=1 rowspan=1 > March 25–April 4 </td><td colspan=1 rowspan=1 > 9 </td><td colspan=1 rowspan=1 > 73 </td><td colspan=1 rowspan=1 > 2444 </td><td colspan=1 rowspan=1 > 6½ </td><td colspan=1 rowspan=1 > Svetozar Gligorić (Yugoslavia) Florin Gheorghiu (Romania) Vladimir Liberzon (Israel) Vlastimil Hort (Czechoslovakia) </td></tr>
<tr> <td colspan=1 rowspan=1 > 1980 </td><td colspan=1 rowspan=1 > March 16–26 </td><td colspan=1 rowspan=1 > 9 </td><td colspan=1 rowspan=1 > 43 </td><td colspan=1 rowspan=1 > 2487 </td><td colspan=1 rowspan=1 > 7 </td><td colspan=1 rowspan=1 > Roman Dzindzichashvili (Israel) </td></tr>
<tr> <td colspan=1 rowspan=1 > 1981 </td><td colspan=1 rowspan=1 > March 29–April 8 </td><td colspan=1 rowspan=1 > 9 </td><td colspan=1 rowspan=1 > 61 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 7 </td><td colspan=1 rowspan=1 > Viktor Korchnoi (Switzerland) </td></tr>
</table>
Question:
When was the United States most successful at Lone Pine International?
Answer:
The United States first won Lone Pine International in 1971 and last won Lone Pine International in 1974.