import re
st='''["FL gr_20 T3\'><strong>+1,921.15</strong>"]' st='["FL gr_20 T3\'><strong>-921.15</strong>"]' st='["FL gr_20 T3\'><strong>21.15</strong>"]' st='["FL gr_20 T3\'><strong>1,11,921.15</strong>"]' st='["FL gr_20 T3\'><strong>1,921</strong>"]' st='["FL gr_20 T3\'><strong>112921</strong>"]' st='["FL gr_20 T3\'><strong>1.15</strong>"]' st='["FL gr_20 T3\'><strong>1</strong>"]'''
print(re.findall(r'>([-+]?\d[\d,.]*)<', st))
aW1wb3J0IHJlCnN0PScnJ1siRkwgZ3JfMjAgVDNcJz48c3Ryb25nPisxLDkyMS4xNTwvc3Ryb25nPiJdJyBzdD0nWyJGTCBncl8yMCBUM1wnPjxzdHJvbmc+LTkyMS4xNTwvc3Ryb25nPiJdJyBzdD0nWyJGTCBncl8yMCBUM1wnPjxzdHJvbmc+MjEuMTU8L3N0cm9uZz4iXScgc3Q9J1siRkwgZ3JfMjAgVDNcJz48c3Ryb25nPjEsMTEsOTIxLjE1PC9zdHJvbmc+Il0nIHN0PSdbIkZMIGdyXzIwIFQzXCc+PHN0cm9uZz4xLDkyMTwvc3Ryb25nPiJdJyBzdD0nWyJGTCBncl8yMCBUM1wnPjxzdHJvbmc+MTEyOTIxPC9zdHJvbmc+Il0nIHN0PSdbIkZMIGdyXzIwIFQzXCc+PHN0cm9uZz4xLjE1PC9zdHJvbmc+Il0nIHN0PSdbIkZMIGdyXzIwIFQzXCc+PHN0cm9uZz4xPC9zdHJvbmc+Il0nJycKcHJpbnQocmUuZmluZGFsbChyJz4oWy0rXT9cZFtcZCwuXSopPCcsIHN0KSk=
['+1,921.15', '-921.15', '21.15', '1,11,921.15', '1,921', '112921', '1.15', '1']