Dear Statalist experts,
I have the following data set, I have been trying to transform this quarterly data into monthly data
I'm still new to this kind of data management, I'm pretty sure this will be easy, yet I couldn't do it, can anyone help me with that

Code:
* Example generated by -dataex-. For more info, type help dataex
clear
input double(ndate pop)
1947.25   101799.864879566
 1947.5  102021.9210454717
1947.75 102244.46158275525
   1948  102467.4875479765
1948.25             102691
 1948.5             102915
1948.75             103249
   1949             103418
1949.25             103584
 1949.5             103838
1949.75             104127
   1950             104428
1950.25             104733
 1950.5             105020
1950.75             105248
   1951             104982
1951.25             104692
 1951.5             104507
1951.75             104543
   1952             104747
1952.25             104863
 1952.5             105007
1952.75             105343
   1953             105703
1953.25             106672
 1953.5             106905
1953.75             107140
   1954             107503
1954.25             107877
 1954.5             108177
1954.75             108443
   1955             108786
1955.25             109130
 1955.5             109534
1955.75             109884
   1956             110186
1956.25             110483
 1956.5             110788
1956.75             111113
   1957             111431
1957.25             111720
 1957.5             112045
1957.75             112431
   1958             112866
1958.25             113236
 1958.5             113532
1958.75             113846
   1959             114283
1959.25             114714
 1959.5             115139
1959.75             115551
   1960             115918
1960.25             116708
 1960.5             117037
1960.75             117411
   1961             117824
1961.25             118254
 1961.5             118636
1961.75             119001
   1962             119190
1962.25             119379
 1962.5             119819
1962.75             120368
   1963             121046
1963.25             121640
 1963.5             122167
1963.75             122670
   1964             123189
1964.25             123708
 1964.5             124203
1964.75             124739
   1965             125289
1965.25             125814
 1965.5             126325
1965.75             126745
   1966             127169
1966.25             127511
 1966.5             127869
1966.75             128234
   1967             128617
1967.25             129044
 1967.5             129527
1967.75             130166
   1968             130757
1968.25             131267
 1968.5             131712
1968.75             132250
   1969             132880
1969.25             133476
 1969.5             134020
1969.75             134595
   1970             135247
1970.25             135950
 1970.5             136676
1970.75             137456
   1971             138260
1971.25             139034
 1971.5             139827
1971.75             140603
   1972             141402
end