name mineral opened closed years connected notes
name
mineral
opened
closed
years connected
notes
number parsed year
number parsed year
minimum_number minimum_parsed minimum_year maximum_number maximum_parsed maximum_year
text text date date timespan text
blaen y cwm slate 1820 1911 1876-1911 connected to the ffr via the rhiwbach tramway
how many quarries opened before 1892 ?
WRB JJ NNS VBD IN CD .
22
Keyword Keyword Keyword Keyword Keyword Keyword Keyword Keyword Column Keyword Literal.Number
select count ( * ) from w where c3_number <= 1892
Keyword Keyword None Column Keyword Literal None
['agg', 'agg_count'] ['agg', 'agg_count'] c3_number ['comp', 'comp_lequal']