Hello,

I hope you are all safe and healthy. I have Stata version 14 and a panel data set consists of World countries for the period 1900-2016. To analyze the data, I would like to build some restrictions on selected countries for a specific period. For instance, for the old Soviet Union countries, I would like to analyze the period after 1995 while analyzing the whole period for the other countries simultaneously. Here you may see how data looks like:

input str52 Area int(Year weather_events) long hdd int cdd
"Afghanistan" 1954 1 . .
"Afghanistan" 1956 2 . .
"Afghanistan" 1960 0 . .
"Afghanistan" 1961 0 . .
"Afghanistan" 1962 0 . .
"Afghanistan" 1963 1 . .
"Afghanistan" 1964 1 . .
"Afghanistan" 1965 0 . .
"Afghanistan" 1966 0 . .
"Afghanistan" 1967 0 . .
"Afghanistan" 1968 0 . .
"Afghanistan" 1969 1 . .
"Afghanistan" 1970 0 . .
"Afghanistan" 1971 2 . .
"Afghanistan" 1972 1 . .
"Afghanistan" 1973 0 . .
"Afghanistan" 1974 0 . .
"Afghanistan" 1975 0 . .
"Afghanistan" 1976 2 . .
"Afghanistan" 1977 0 . .
"Afghanistan" 1978 1 . .
"Afghanistan" 1979 0 . .
"Afghanistan" 1980 1 . .
"Afghanistan" 1981 0 . .
"Afghanistan" 1982 1 . .
"Afghanistan" 1983 1 . .
"Afghanistan" 1984 1 . .
"Afghanistan" 1985 0 . .
"Afghanistan" 1986 0 . .
"Afghanistan" 1987 1 . .
"Afghanistan" 1988 1 . .
"Afghanistan" 1989 2 . .
"Afghanistan" 1990 3 . .
"Afghanistan" 1991 8 . .
"Afghanistan" 1992 3 . .
"Afghanistan" 1993 5 . .
"Afghanistan" 1994 1 . .
"Afghanistan" 1995 3 . .
"Afghanistan" 1996 3 . .
"Afghanistan" 1997 6 . .
"Afghanistan" 1998 8 . .
"Afghanistan" 1999 5 . .
"Afghanistan" 2000 6 . .
"Afghanistan" 2001 7 . .
"Afghanistan" 2002 20 . .
"Afghanistan" 2003 10 . .
"Afghanistan" 2004 6 . .
"Afghanistan" 2005 20 . .
"Afghanistan" 2006 15 . .
"Afghanistan" 2007 8 . .
"Afghanistan" 2008 5 . .
"Afghanistan" 2009 8 . .
"Afghanistan" 2010 9 . .
"Afghanistan" 2011 7 . .
"Afghanistan" 2012 12 . .
"Afghanistan" 2013 8 . .
"Afghanistan" 2014 3 . .
"Afghanistan" 2015 9 . .
"Afghanistan" 2016 6 . .
"Afghanistan" 2017 6 . .
"Afghanistan" 2018 10 . .
"Afghanistan" 2019 7 . .
"Afghanistan" 2020 1 . .
"Albania" 1905 1 . .
"Albania" 1920 1 . .
"Albania" 1930 2 . .
"Albania" 1931 1 . .
"Albania" 1942 1 . .
"Albania" 1960 0 15805 2406
"Albania" 1961 0 16471 2653
"Albania" 1962 0 16847 3281
"Albania" 1963 0 17412 2812
"Albania" 1964 0 17628 1966
"Albania" 1965 0 17727 2724
"Albania" 1966 0 16500 2167
"Albania" 1967 1 17303 2800

I used the following command and faced with an error.

Code:
drop Year<1995 if Area=="Armenia"

Thank you in advance.